https://epg.modot.org/index.php?title=231.2_Clear_Zones&feed=atom&action=history231.2 Clear Zones - Revision history2024-03-29T08:47:11ZRevision history for this page on the wikiMediaWiki 1.33.1https://epg.modot.org/index.php?title=231.2_Clear_Zones&diff=48966&oldid=prevSmithk: /* 231.2.1 Introduction */ Per TS, minor clarifications2021-02-16T14:51:15Z<p><span dir="auto"><span class="autocomment">231.2.1 Introduction: </span> Per TS, minor clarifications</span></p>
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<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>Where resources and safety benefits justify the use of clear zones, clear zone concepts may be applied to existing roads to address roadside obstacles and non-traversable terrain. Clear zones are reviewed and/or selected based on the RDG guidelines during the preparation of the location/conceptual study report. </div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>Where resources and safety benefits justify the use of clear zones, clear zone concepts may be applied to existing roads to address roadside obstacles and non-traversable terrain. Clear zones are reviewed and/or selected based on the RDG guidelines during the preparation of the location/conceptual study report. </div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div> </div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div> </div></td></tr>
<tr><td class='diff-marker'>−</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>The clear zone concept shall be applied with engineering judgment including <del class="diffchange diffchange-inline">a safety analysis (Highway Safety Manual or HSM) </del>and be balanced with project costs. Limited right of way or high construction costs may lead to the installation of a barrier or possibly no protection at all if justified through a safety analysis. <del class="diffchange diffchange-inline"> </del>The designer should consider site specific characteristics of the roadway at issue including, if appropriate, the location of the object or area in relation to the roadway, road width, lane width, traffic volume, design speed, roadway geometry, and the crash history (including severity) involving the roadside object or area when analyzing whether or not to install a barrier. <del class="diffchange diffchange-inline"> </del>Documentation of decisions regarding clear zone strategies shall be included in the project conceptual study report, project core team minutes, or design exception forms, and shall be filed in eProjects. </div></td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>The clear zone concept shall be applied with engineering judgment including <ins class="diffchange diffchange-inline">consideration of severe crash risk </ins>and be balanced with project costs. <ins class="diffchange diffchange-inline">Resources to assist this decision-making includes the ''Roadside Design Guide'', history of run-off road crashes, and the ''Highway Safety Manual'' (HSM). </ins>Limited right of way or high construction costs may lead to the installation of a barrier or possibly no protection at all if justified through a safety analysis. The designer should consider site specific characteristics of the roadway at issue including, if appropriate, the location of the object or area in relation to the roadway, road width, lane width, traffic volume, design speed, roadway geometry, and the crash history (including severity) involving the roadside object or area when analyzing whether or not to install a barrier. Documentation of decisions regarding clear zone strategies shall be included in the project <ins class="diffchange diffchange-inline">scoping, </ins>conceptual study report, project core team minutes, or design exception forms, and shall be filed in eProjects. </div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>Maintenance staff may remove trees, boulders, or other obstacles on existing roads where right-of-way is available. This cleared area shall not be assumed a designed clear zone as used in the EPG. If a safety concern is identified during a roadway safety audit or a project core team meeting, then the safety concern should be considered and discussed with the core team in the context of project budget and scope.</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>Maintenance staff may remove trees, boulders, or other obstacles on existing roads where right-of-way is available. This cleared area shall not be assumed a designed clear zone as used in the EPG. If a safety concern is identified during a roadway safety audit or a project core team meeting, then the safety concern should be considered and discussed with the core team in the context of project budget and scope.</div></td></tr>
</table>Smithkhttps://epg.modot.org/index.php?title=231.2_Clear_Zones&diff=48932&oldid=prevKleins1: /* 231.2.4 Ramps */2021-02-02T14:41:37Z<p><span dir="auto"><span class="autocomment">231.2.4 Ramps</span></span></p>
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<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>===231.2.4 Ramps===</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>===231.2.4 Ramps===</div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td></tr>
<tr><td class='diff-marker'>−</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>Clear zones should be considered on ramps <del class="diffchange diffchange-inline">when</del>. Shielding may <del class="diffchange diffchange-inline">also </del>be applicable with engineering judgment at these locations. Special consideration should be given at ramp termini where stop conditions exist. It may be acceptable to leave a non-traversable slope unshielded when operating speeds that approach zero are to be expected, especially when barriers in those areas become obstacles and receive continual damage from low speed, turning, commercial vehicle traffic.</div></td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>Clear zones should be considered on ramps. Shielding may be applicable with engineering judgment at these locations. Special consideration should be given at ramp termini where stop conditions exist. It may be acceptable to leave a non-traversable slope unshielded when operating speeds that approach zero are to be expected, especially when barriers in those areas become obstacles and receive continual damage from low speed, turning, commercial vehicle traffic.</div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>===231.2.5 Unusual Conditions===</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>===231.2.5 Unusual Conditions===</div></td></tr>
</table>Kleins1https://epg.modot.org/index.php?title=231.2_Clear_Zones&diff=48931&oldid=prevKleins1: /* 231.2.3 For Bridges and Culverts */2021-02-02T14:39:59Z<p><span dir="auto"><span class="autocomment">231.2.3 For Bridges and Culverts</span></span></p>
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<td colspan="2" style="background-color: #fff; color: #222; text-align: center;">Revision as of 14:39, 2 February 2021</td>
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<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>Where the existing roadway is to be incorporated into a newly constructed facility as part of the main roadway, the use of clear zones will be considered on individual projects. For “spot improvements” such as bridge replacements, the designer may determine to use less than the prescribed clear zone for new construction. This decision should be based on engineering judgment, giving consideration to crash history, roadway characteristics, access issues, project scope, and budget.</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>Where the existing roadway is to be incorporated into a newly constructed facility as part of the main roadway, the use of clear zones will be considered on individual projects. For “spot improvements” such as bridge replacements, the designer may determine to use less than the prescribed clear zone for new construction. This decision should be based on engineering judgment, giving consideration to crash history, roadway characteristics, access issues, project scope, and budget.</div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td></tr>
<tr><td class='diff-marker'>−</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>The use of [[:Category:231 Typical Section Elements for Roadways|clear zone typical sections is not applicable to small culvert replacement projects where the intent is to continue the service of the road without upgrading it. In such cases, the typical sections in the original construction are to be used except the roadway width is not to be narrower than the template of the roadway approaching the improvement. </div></td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>The use of [[:Category:231 Typical Section Elements for Roadways|clear zone typical sections<ins class="diffchange diffchange-inline">]] </ins>is not applicable to small culvert replacement projects where the intent is to continue the service of the road without upgrading it. In such cases, the typical sections in the original construction are to be used except the roadway width is not to be narrower than the template of the roadway approaching the improvement. </div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div> </div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div> </div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>In shallow fills and in cuts where box or pipe culvert normally require a headwall to be located in the clear zone, the location of the headwall will be determined after an appropriate safety analysis is conducted. The culvert extension, shielding, audible warnings (rumble strips), delineation and the like (or combination of these) should be considered within the scope and budget of the project.</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>In shallow fills and in cuts where box or pipe culvert normally require a headwall to be located in the clear zone, the location of the headwall will be determined after an appropriate safety analysis is conducted. The culvert extension, shielding, audible warnings (rumble strips), delineation and the like (or combination of these) should be considered within the scope and budget of the project.</div></td></tr>
</table>Kleins1https://epg.modot.org/index.php?title=231.2_Clear_Zones&diff=48930&oldid=prevKleins1: /* 231.2.3 For Bridges and Culverts */2021-02-02T14:39:05Z<p><span dir="auto"><span class="autocomment">231.2.3 For Bridges and Culverts</span></span></p>
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<td colspan="2" style="background-color: #fff; color: #222; text-align: center;">Revision as of 14:39, 2 February 2021</td>
</tr><tr><td colspan="2" class="diff-lineno" id="mw-diff-left-l53" >Line 53:</td>
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<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>Where the existing roadway is to be incorporated into a newly constructed facility as part of the main roadway, the use of clear zones will be considered on individual projects. For “spot improvements” such as bridge replacements, the designer may determine to use less than the prescribed clear zone for new construction. This decision should be based on engineering judgment, giving consideration to crash history, roadway characteristics, access issues, project scope, and budget.</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>Where the existing roadway is to be incorporated into a newly constructed facility as part of the main roadway, the use of clear zones will be considered on individual projects. For “spot improvements” such as bridge replacements, the designer may determine to use less than the prescribed clear zone for new construction. This decision should be based on engineering judgment, giving consideration to crash history, roadway characteristics, access issues, project scope, and budget.</div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td></tr>
<tr><td class='diff-marker'>−</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>The use of [[:Category:231 Typical Section Elements for Roadways|<del class="diffchange diffchange-inline">clear zone typical sections]] is not applicable to small culvert replacement projects where the intent is to continue the service of the road without upgrading it. In such cases, the typical sections used in the original construction are to be used except that the roadbed width is not to be more narrow than 24 feet.</del></div></td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>The use of [[:Category:231 Typical Section Elements for Roadways|clear zone typical sections is not applicable to small culvert replacement projects where the intent is to continue the service of the road without upgrading it. In such cases, the typical sections in the original construction are to be used except the roadway width is not to be narrower than the template of the roadway approaching the improvement. </div></td></tr>
<tr><td class='diff-marker'>−</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div> </div></td><td colspan="2"> </td></tr>
<tr><td class='diff-marker'>−</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div><del class="diffchange diffchange-inline">The use of </del>clear zone typical sections is not applicable to small culvert replacement projects where the intent is to continue the service of the road without upgrading it. In such cases, the typical sections in the original construction are to be used except the roadway width is not to be narrower than the template of the roadway approaching the improvement. </div></td><td colspan="2"> </td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div> </div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div> </div></td></tr>
<tr><td class='diff-marker'>−</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>In shallow fills and in cuts where box or pipe culvert normally require a headwall to be located in the clear zone, the location of the headwall will be determined after an appropriate safety analysis is conducted. The culvert extension, shielding, audible warnings (rumble strips), delineation and the like (or combination of these) should be considered within the scope and budget of the project. </div></td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>In shallow fills and in cuts where box or pipe culvert normally require a headwall to be located in the clear zone, the location of the headwall will be determined after an appropriate safety analysis is conducted. The culvert extension, shielding, audible warnings (rumble strips), delineation and the like (or combination of these) should be considered within the scope and budget of the project.</div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>===231.2.4 Ramps===</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>===231.2.4 Ramps===</div></td></tr>
</table>Kleins1https://epg.modot.org/index.php?title=231.2_Clear_Zones&diff=48921&oldid=prevSmithk: Per DE, guidance now incorporates additional Roadside Design Guide (RDG) verbiage, RDG tables, and recommends a safety analysis as a means of documenting decisions for safety strategies.2021-02-01T18:53:02Z<p>Per DE, guidance now incorporates additional Roadside Design Guide (RDG) verbiage, RDG tables, and recommends a safety analysis as a means of documenting decisions for safety strategies.</p>
<a href="https://epg.modot.org/index.php?title=231.2_Clear_Zones&diff=48921&oldid=44610">Show changes</a>Smithkhttps://epg.modot.org/index.php?title=231.2_Clear_Zones&diff=44610&oldid=prevSmithk at 15:09, 25 January 20192019-01-25T15:09:43Z<p></p>
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<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>|[[:Category:231 Typical Section Elements for Roadways|Roadway Typical Sections]]</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>|[[:Category:231 Typical Section Elements for Roadways|Roadway Typical Sections]]</div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>|-</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>|-</div></td></tr>
<tr><td class='diff-marker'>−</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>|[[media:231.2 Clear Zone Distance.<del class="diffchange diffchange-inline">pdf</del>|RDG Table 3-1 "Suggested Clear-Zone Distances from Edge of Through Traveled Lane"]]</div></td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>|[[media:231.2 Clear Zone Distance <ins class="diffchange diffchange-inline">2019</ins>.<ins class="diffchange diffchange-inline">docx</ins>|RDG Table 3-1 "Suggested Clear-Zone Distances from Edge of Through Traveled Lane"]]</div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>|-</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>|-</div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>|[[media:231.2 Horizontal Curve Adjustments.jpg|RDG Table 3-2 "Horizontal Curve Adjustment Factor"]]</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>|[[media:231.2 Horizontal Curve Adjustments.jpg|RDG Table 3-2 "Horizontal Curve Adjustment Factor"]]</div></td></tr>
</table>Smithkhttps://epg.modot.org/index.php?title=231.2_Clear_Zones&diff=43622&oldid=prevSmithk: Per Chuck Schumann, updated RDG Table 3-1 to reflect July 2015 errata2018-09-14T15:04:52Z<p>Per Chuck Schumann, updated RDG Table 3-1 to reflect July 2015 errata</p>
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<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>|[[:Category:231 Typical Section Elements for Roadways|Roadway Typical Sections]]</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>|[[:Category:231 Typical Section Elements for Roadways|Roadway Typical Sections]]</div></td></tr>
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<tr><td class='diff-marker'>−</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>|[[media:231.2 Clear Zone Distance.<del class="diffchange diffchange-inline">docx</del>|RDG Table 3-1 "Suggested Clear-Zone Distances from Edge of Through Traveled Lane"]]</div></td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>|[[media:231.2 Clear Zone Distance.<ins class="diffchange diffchange-inline">pdf</ins>|RDG Table 3-1 "Suggested Clear-Zone Distances from Edge of Through Traveled Lane"]]</div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>|-</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>|-</div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>|[[media:231.2 Horizontal Curve Adjustments.jpg|RDG Table 3-2 "Horizontal Curve Adjustment Factor"]]</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>|[[media:231.2 Horizontal Curve Adjustments.jpg|RDG Table 3-2 "Horizontal Curve Adjustment Factor"]]</div></td></tr>
</table>Smithkhttps://epg.modot.org/index.php?title=231.2_Clear_Zones&diff=43267&oldid=prevSmithk: /* 231.2.1 Introduction */2018-08-14T18:25:21Z<p><span dir="auto"><span class="autocomment">231.2.1 Introduction</span></span></p>
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<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>|[[:Category:231 Typical Section Elements for Roadways|Roadway Typical Sections]]</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>|[[:Category:231 Typical Section Elements for Roadways|Roadway Typical Sections]]</div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>|-</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>|-</div></td></tr>
<tr><td class='diff-marker'>−</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>|[[media:231.2 Clear Zone Distance.docx|RDG Table 3<del class="diffchange diffchange-inline">.</del>1 "Suggested Clear-Zone Distances from Edge of Through Traveled Lane"]]</div></td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>|[[media:231.2 Clear Zone Distance.docx|RDG Table 3<ins class="diffchange diffchange-inline">-</ins>1 "Suggested Clear-Zone Distances from Edge of Through Traveled Lane"]]</div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>|-</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>|-</div></td></tr>
<tr><td class='diff-marker'>−</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>|[[media:231.2 Horizontal Curve Adjustments.jpg|RDG Table 3<del class="diffchange diffchange-inline">.</del>2 "Horizontal Curve Adjustment Factor"]]</div></td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>|[[media:231.2 Horizontal Curve Adjustments.jpg|RDG Table 3<ins class="diffchange diffchange-inline">-</ins>2 "Horizontal Curve Adjustment Factor"]]</div></td></tr>
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<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>|[[media:231.2 Clear Zone for Non-recoverable.jpg|RDG Figure 3-2 "Clear Zone for Non-Recoverable Parallel Foreslope"]]</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>|[[media:231.2 Clear Zone for Non-recoverable.jpg|RDG Figure 3-2 "Clear Zone for Non-Recoverable Parallel Foreslope"]]</div></td></tr>
</table>Smithkhttps://epg.modot.org/index.php?title=231.2_Clear_Zones&diff=43261&oldid=prevSmithk: Per EPS, clarified clear zone guidance2018-08-14T18:17:10Z<p>Per EPS, clarified clear zone guidance</p>
<table class="diff diff-contentalign-left" data-mw="interface">
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<td colspan="2" style="background-color: #fff; color: #222; text-align: center;">Revision as of 18:17, 14 August 2018</td>
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<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>===231.2.1 Introduction===</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>===231.2.1 Introduction===</div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td></tr>
<tr><td class='diff-marker'>−</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>The [[media:231.2 Examples of a Parallel Foreslope Design.pdf|clear zone]] concept is the road design principle of providing an unobstructed, traversable area beyond the edge of the through traveled way for the recovery of errant vehicles. The concept was developed in the 1960s and later incorporated into the ''Roadside Design Guide'' (RDG). The RDG <del class="diffchange diffchange-inline">recommends </del>distances <del class="diffchange diffchange-inline">for particular design conditions</del>. These distances are neither absolute nor precise and, in some cases, it may be reasonable to leave a fixed object or non-traversable terrain within the clear zone area. The clear zone concept <del class="diffchange diffchange-inline">is '''mostly''' </del>applicable to new construction and <del class="diffchange diffchange-inline">major </del>reconstruction. <del class="diffchange diffchange-inline">In limited circumstances, specific fixed </del>objects and non-traversable terrain features may be addressed on existing roads as part of resurfacing (1R) or resurfacing and restoration (2R) projects (see [[:Category:128 Conceptual Studies#128.2 Preventive Maintenance Projects (1R and 2R)|EPG 128.2 Preventive Maintenance Projects (1R and 2R)]]). On existing roads, primarily those of an older or lower-order nature, a clear area may be established through maintenance activities. While this practice is strongly encouraged, these areas should not be construed as providing the same safety benefit as clear zones. </div></td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>The [[media:231.2 Examples of a Parallel Foreslope Design.pdf|clear zone]] concept is the road design principle of providing an unobstructed, traversable area beyond the edge of the through traveled way for the recovery of errant vehicles. The concept was developed in the 1960s and later incorporated into the ''Roadside Design Guide'' (RDG). The RDG <ins class="diffchange diffchange-inline">suggests clear zone </ins>distances <ins class="diffchange diffchange-inline">based on traffic volumes and speeds</ins>. These distances are neither absolute nor precise and, in some cases, it may be reasonable to leave a fixed object or non-traversable terrain within the clear zone area. <ins class="diffchange diffchange-inline">Roadside design strategies involve the following:</ins></div></td></tr>
<tr><td class='diff-marker'>−</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>{|style="padding: 0.3em; margin-left:15px; border:1px solid #a9a9a9; text-align:center; font-size: 95%; background:#f5f5f5" width="<del class="diffchange diffchange-inline">220px</del>" align="right"</div></td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div> </div></td></tr>
<tr><td colspan="2"> </td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div><ins class="diffchange diffchange-inline">:1. Remove the obstacle</ins></div></td></tr>
<tr><td colspan="2"> </td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div><ins class="diffchange diffchange-inline">:2. Redesign the obstacle for safe traversal</ins></div></td></tr>
<tr><td colspan="2"> </td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div><ins class="diffchange diffchange-inline">:3. Relocate the obstacle further from the roadway</ins></div></td></tr>
<tr><td colspan="2"> </td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div><ins class="diffchange diffchange-inline">:4. Reduce obstacle severity (make it breakaway)</ins></div></td></tr>
<tr><td colspan="2"> </td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div><ins class="diffchange diffchange-inline">:5. Shield the obstacle</ins></div></td></tr>
<tr><td colspan="2"> </td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div><ins class="diffchange diffchange-inline">:6. Delineate the obstacle (when we must leave the obstacle)</ins></div></td></tr>
<tr><td colspan="2"> </td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div> </div></td></tr>
<tr><td colspan="2"> </td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>The clear zone concept <ins class="diffchange diffchange-inline">guidelines in the RDG may be most </ins>applicable to new construction and <ins class="diffchange diffchange-inline"> </ins>reconstruction<ins class="diffchange diffchange-inline">/rehabilitation projects</ins>. <ins class="diffchange diffchange-inline">Fixed </ins>objects and non-traversable terrain features may <ins class="diffchange diffchange-inline">also </ins>be addressed on existing roads as part of resurfacing (1R) or resurfacing and restoration (2R) projects (see [[:Category:128 Conceptual Studies#128.2 Preventive Maintenance Projects (1R and 2R)|EPG 128.2 Preventive Maintenance Projects (1R and 2R)]])<ins class="diffchange diffchange-inline">. Every roadside should be made as safe as practical</ins>. On existing roads, primarily those of an older or lower-order nature, a clear area may be established through maintenance activities. While this practice is strongly encouraged, these areas should not be construed as providing the same safety benefit as clear zones. </div></td></tr>
<tr><td colspan="2"> </td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>{|style="padding: 0.3em; margin-left:15px; border:1px solid #a9a9a9; text-align:center; font-size: 95%; background:#f5f5f5" width="<ins class="diffchange diffchange-inline">280px</ins>" align="right"</div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>|-</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>|-</div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>|'''Figures'''</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>|'''Figures'''</div></td></tr>
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<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>|[[:Category:231 Typical Section Elements for Roadways|Roadway Typical Sections]]</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>|[[:Category:231 Typical Section Elements for Roadways|Roadway Typical Sections]]</div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>|-</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>|-</div></td></tr>
<tr><td class='diff-marker'>−</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>|[[media:231.2 Clear Zone Distance <del class="diffchange diffchange-inline">Curves</del>.<del class="diffchange diffchange-inline">pdf</del>|RDG <del class="diffchange diffchange-inline">Figure </del>3.1 "Clear-Zone <del class="diffchange diffchange-inline">Distance curves</del>"]]</div></td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>|[[media:231.2 Clear Zone Distance.<ins class="diffchange diffchange-inline">docx</ins>|RDG <ins class="diffchange diffchange-inline">Table </ins>3.1 "<ins class="diffchange diffchange-inline">Suggested </ins>Clear-Zone <ins class="diffchange diffchange-inline">Distances from Edge of Through Traveled Lane</ins>"]]</div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>|-</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>|-</div></td></tr>
<tr><td class='diff-marker'>−</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>|[[media:231.2 Horizontal Curve Adjustments.<del class="diffchange diffchange-inline">pdf</del>|RDG Table 3.2 "Horizontal Curve <del class="diffchange diffchange-inline">Adjustments</del>"]]</div></td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>|[[media:231.2 Horizontal Curve Adjustments.<ins class="diffchange diffchange-inline">jpg</ins>|RDG Table 3.2 "Horizontal Curve <ins class="diffchange diffchange-inline">Adjustment Factor</ins>"]]</div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>|-</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>|-</div></td></tr>
<tr><td class='diff-marker'>−</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>|[[media:231.2 <del class="diffchange diffchange-inline">Examples of a Parallel Foreslope Design</del>.<del class="diffchange diffchange-inline">pdf</del>|RDG Figure 3<del class="diffchange diffchange-inline">.</del>2 "<del class="diffchange diffchange-inline">Example of a </del>Parallel Foreslope <del class="diffchange diffchange-inline">Design</del>"]]</div></td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>|[[media:231.2 <ins class="diffchange diffchange-inline">Clear Zone for Non-recoverable</ins>.<ins class="diffchange diffchange-inline">jpg</ins>|RDG Figure 3<ins class="diffchange diffchange-inline">-</ins>2 "<ins class="diffchange diffchange-inline">Clear Zone for Non-Recoverable </ins>Parallel Foreslope"]]</div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>|-</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>|-</div></td></tr>
<tr><td class='diff-marker'>−</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>|[[media:231.2 Preferred Cross Sections <del class="diffchange diffchange-inline">for Channels with abrupt slope changes</del>.<del class="diffchange diffchange-inline">pdf</del>|RDG Figure 3<del class="diffchange diffchange-inline">.</del>6 "Preferred Cross Sections for Channels with Abrupt Slope Changes"]]</div></td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>|[[media:231.2 Preferred Cross Sections.<ins class="diffchange diffchange-inline">jpg</ins>|RDG Figure 3<ins class="diffchange diffchange-inline">-</ins>6 "Preferred Cross Sections for Channels with Abrupt Slope Changes"]]</div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>|}</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>|}</div></td></tr>
<tr><td class='diff-marker'>−</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>Clear <del class="diffchange diffchange-inline">zone widths </del>are <del class="diffchange diffchange-inline">most affected by the traffic’s speed </del>and <del class="diffchange diffchange-inline">volume and the slope of the area adjacent to the travelway. Appropriate clear zones are </del>selected <del class="diffchange diffchange-inline">for new construction or major reconstruction projects using [[media:231.2 Clear Zone Distance Curves.pdf|Figure 3.1]] from </del>the RDG after consulting the [[:Category:126 Location Study and Alternatives Analysis|location study report]].</div></td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div> </div></td></tr>
<tr><td colspan="2"> </td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>Clear <ins class="diffchange diffchange-inline">zones </ins>are <ins class="diffchange diffchange-inline">reviewed </ins>and<ins class="diffchange diffchange-inline">/or </ins>selected <ins class="diffchange diffchange-inline">based on </ins>the RDG <ins class="diffchange diffchange-inline">guidelines </ins>after consulting the [[:Category:126 Location Study and Alternatives Analysis|location study report]].</div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>Clear zones are designed into a project when the anticipated posted speed of the roadway is 45 mph or more. When the anticipated posted speed is less than 45 mph, clear zones are still beneficial, but they are to be considered only if economically feasible. Non-traversable slopes or fixed objects are to be removed, redesigned, relocated or shielded by a barrier if they are within the indicated minimum clear zone width and it is cost effective to do so. </div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>Clear zones are designed into a project when the anticipated posted speed of the roadway is 45 mph or more. When the anticipated posted speed is less than 45 mph, clear zones are still beneficial, but they are to be considered only if economically feasible. Non-traversable slopes or fixed objects are to be removed, redesigned, relocated or shielded by a barrier if they are within the indicated minimum clear zone width and it is cost effective to do so. </div></td></tr>
<tr><td colspan="2" class="diff-lineno" id="mw-diff-left-l36" >Line 36:</td>
<td colspan="2" class="diff-lineno">Line 46:</td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>Clear zones, when used, shall extend full-width to bridge ends. Where the existing roadway is to be incorporated into the completed facility as part of the main roadway, the use of clear zones will be considered on individual projects.</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>Clear zones, when used, shall extend full-width to bridge ends. Where the existing roadway is to be incorporated into the completed facility as part of the main roadway, the use of clear zones will be considered on individual projects.</div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td></tr>
<tr><td class='diff-marker'>−</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>The use of [[:Category:231 Typical Section Elements for Roadways|clear zone typical sections]] is not applicable to small culvert replacement projects where the intent is to continue the service of the road without upgrading it. In such cases, the typical sections used in the original construction are to be used except that the roadbed width is not to be more narrow than 24 <del class="diffchange diffchange-inline">ft</del>.</div></td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>The use of [[:Category:231 Typical Section Elements for Roadways|clear zone typical sections]] is not applicable to small culvert replacement projects where the intent is to continue the service of the road without upgrading it. In such cases, the typical sections used in the original construction are to be used except that the roadbed width is not to be more narrow than 24 <ins class="diffchange diffchange-inline">feet</ins>.</div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>In shallow fills and in cuts where box or pipe culvert normally require a headwall to be located in the clear zone, the structure should be extended to place the headwall at the outside of the clear zone or a safety appurtenance (guardrail or barrier) should be provided. The slope of the clear zone will then require modification over the entire surface.</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>In shallow fills and in cuts where box or pipe culvert normally require a headwall to be located in the clear zone, the structure should be extended to place the headwall at the outside of the clear zone or a safety appurtenance (guardrail or barrier) should be provided. The slope of the clear zone will then require modification over the entire surface.</div></td></tr>
<tr><td colspan="2" class="diff-lineno" id="mw-diff-left-l46" >Line 46:</td>
<td colspan="2" class="diff-lineno">Line 56:</td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>===231.2.5 In Unusual Conditions===</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>===231.2.5 In Unusual Conditions===</div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td></tr>
<tr><td class='diff-marker'>−</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>When a standard clear zone width and slope will not properly terminate on the existing ground surface because of hilly conditions, steeper slopes must be used. In this case, the clear zone may be omitted and guardrail used at the shoulder line. The desirable minimum length for the elimination of clear zone is 500 ft. but in no case less than 250 <del class="diffchange diffchange-inline">ft</del>. </div></td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>When a standard clear zone width and slope will not properly terminate on the existing ground surface because of hilly conditions, steeper slopes must be used. In this case, the clear zone may be omitted and guardrail used at the shoulder line. The desirable minimum length for the elimination of clear zone is 500 ft. but in no case less than 250 <ins class="diffchange diffchange-inline">feet</ins>. </div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>For long fill sections through a reservoir project, clear zones can be eliminated and guardrail used at the shoulder lines.</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>For long fill sections through a reservoir project, clear zones can be eliminated and guardrail used at the shoulder lines.</div></td></tr>
<tr><td colspan="2" class="diff-lineno" id="mw-diff-left-l54" >Line 54:</td>
<td colspan="2" class="diff-lineno">Line 64:</td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>===231.2.6 Maintenance===</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>===231.2.6 Maintenance===</div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td></tr>
<tr><td class='diff-marker'>−</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>District personnel shall be responsible for maintaining clear zones on <del class="diffchange diffchange-inline">highway improvement projects</del>.</div></td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>District personnel shall be responsible for maintaining clear zones on <ins class="diffchange diffchange-inline">highways</ins>.</div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>[[category:231 Typical Section Elements for Roadways|231.02]]</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>[[category:231 Typical Section Elements for Roadways|231.02]]</div></td></tr>
</table>Smithkhttps://epg.modot.org/index.php?title=231.2_Clear_Zones&diff=40305&oldid=prevEPGsysop: /* 231.2.1 Introduction */ Per EPS and CCO, condensed and clarified guidance regarding clear zones and roadside hardware for 1R and 2R projects2018-02-01T20:53:56Z<p><span dir="auto"><span class="autocomment">231.2.1 Introduction: </span> Per EPS and CCO, condensed and clarified guidance regarding clear zones and roadside hardware for 1R and 2R projects</span></p>
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<td colspan="2" style="background-color: #fff; color: #222; text-align: center;">Revision as of 20:53, 1 February 2018</td>
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<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>===231.2.1 Introduction===</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>===231.2.1 Introduction===</div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td></tr>
<tr><td class='diff-marker'>−</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>The [[media:231.2 Examples of a Parallel Foreslope Design.pdf|clear zone]] is an unobstructed, traversable area <del class="diffchange diffchange-inline">provided </del>beyond the edge of the through traveled way for the recovery of errant vehicles. The <del class="diffchange diffchange-inline">provision of </del>a clear zone is <del class="diffchange diffchange-inline">only </del>applicable to new construction and <del class="diffchange diffchange-inline">re</del>-<del class="diffchange diffchange-inline">construction </del>projects <del class="diffchange diffchange-inline">pursuant to guidance outlined in the Roadside Design Guide</del>. <del class="diffchange diffchange-inline"> </del>On existing roads, primarily those of an older or lower-order nature, a clear area <del class="diffchange diffchange-inline">has been </del>established through maintenance activities. <del class="diffchange diffchange-inline"> </del>While this practice is strongly encouraged, these areas should not be construed as providing the same safety benefit as clear zones<del class="diffchange diffchange-inline">.</del></div></td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>The [[media:231.2 Examples of a Parallel Foreslope Design.pdf|clear zone]] <ins class="diffchange diffchange-inline">concept </ins>is <ins class="diffchange diffchange-inline">the road design principle of providing </ins>an unobstructed, traversable area beyond the edge of the through traveled way for the recovery of errant vehicles. The <ins class="diffchange diffchange-inline">concept was developed in the 1960s and later incorporated into the ''Roadside Design Guide'' (RDG). The RDG recommends distances for particular design conditions. These distances are neither absolute nor precise and, in some cases, it may be reasonable to leave </ins>a <ins class="diffchange diffchange-inline">fixed object or non-traversable terrain within the </ins>clear zone <ins class="diffchange diffchange-inline">area. The clear zone concept </ins>is <ins class="diffchange diffchange-inline">'''mostly''' </ins>applicable to new construction and <ins class="diffchange diffchange-inline">major reconstruction. In limited circumstances, specific fixed objects and non</ins>-<ins class="diffchange diffchange-inline">traversable terrain features may be addressed on existing roads as part of resurfacing (1R) or resurfacing and restoration (2R) </ins>projects <ins class="diffchange diffchange-inline">(see [[:Category:128 Conceptual Studies#128.2 Preventive Maintenance Projects (1R and 2R)|EPG 128.2 Preventive Maintenance Projects (1R and 2R)]])</ins>. On existing roads, primarily those of an older or lower-order nature, a clear area <ins class="diffchange diffchange-inline">may be </ins>established through maintenance activities. While this practice is strongly encouraged, these areas should not be construed as providing the same safety benefit as clear zones. </div></td></tr>
<tr><td class='diff-marker'>−</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div> </div></td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>{|style="padding: 0.3em; margin-left:15px; border:1px solid #a9a9a9; text-align:center; font-size: 95%; background:#f5f5f5" width="<ins class="diffchange diffchange-inline">220px</ins>" align="right"</div></td></tr>
<tr><td class='diff-marker'>−</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div><del class="diffchange diffchange-inline">In general, the clear zone, or forgiving roadside concept is the preferred method of achieving roadside safety. The four methods of establishing a clear zone are listed here in order of preference:</del></div></td><td colspan="2"> </td></tr>
<tr><td class='diff-marker'>−</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div> </div></td><td colspan="2"> </td></tr>
<tr><td class='diff-marker'>−</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div><del class="diffchange diffchange-inline">:1) Eliminate obstacles.</del></div></td><td colspan="2"> </td></tr>
<tr><td class='diff-marker'>−</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div><del class="diffchange diffchange-inline">:2) Redesign obstacles so they can be safely traversed.</del></div></td><td colspan="2"> </td></tr>
<tr><td class='diff-marker'>−</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div><del class="diffchange diffchange-inline">:3) Relocate obstacles to a location where they're less likely to be struck.</del></div></td><td colspan="2"> </td></tr>
<tr><td class='diff-marker'>−</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div><del class="diffchange diffchange-inline">:4) Reduce the impact severity of obstacles by using appropriate breakaway devices</del>.</div></td><td colspan="2"> </td></tr>
<tr><td class='diff-marker'>−</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>{|style="padding: 0.3em; margin-left:15px; border:1px solid #a9a9a9; text-align:center; font-size: 95%; background:#f5f5f5" width="<del class="diffchange diffchange-inline">160px</del>" align="right"</div></td><td colspan="2"> </td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>|-</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>|-</div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>|'''Figures'''</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>|'''Figures'''</div></td></tr>
<tr><td colspan="2" class="diff-lineno" id="mw-diff-left-l25" >Line 25:</td>
<td colspan="2" class="diff-lineno">Line 18:</td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>|[[media:231.2 Preferred Cross Sections for Channels with abrupt slope changes.pdf|RDG Figure 3.6 "Preferred Cross Sections for Channels with Abrupt Slope Changes"]]</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>|[[media:231.2 Preferred Cross Sections for Channels with abrupt slope changes.pdf|RDG Figure 3.6 "Preferred Cross Sections for Channels with Abrupt Slope Changes"]]</div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>|}</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>|}</div></td></tr>
<tr><td class='diff-marker'>−</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>Clear zone widths are most affected by the traffic’s speed and volume and the slope of the area adjacent to the travelway. <del class="diffchange diffchange-inline"> </del>Appropriate clear zones are selected for projects using [[media:231.2 Clear Zone Distance Curves.pdf|Figure 3.1]] from the RDG after consulting the [[:Category:126 Location Study and Alternatives Analysis|location study report]].</div></td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>Clear zone widths are most affected by the traffic’s speed and volume and the slope of the area adjacent to the travelway. Appropriate clear zones are selected for <ins class="diffchange diffchange-inline">new construction or major reconstruction </ins>projects using [[media:231.2 Clear Zone Distance Curves.pdf|Figure 3.1]] from the RDG after consulting the [[:Category:126 Location Study and Alternatives Analysis|location study report]].</div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td></tr>
<tr><td class='diff-marker'>−</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>Clear zones are <del class="diffchange diffchange-inline">provided where </del>the anticipated posted speed of the roadway is 45 mph or more. <del class="diffchange diffchange-inline"> </del>When the anticipated posted speed is less than 45 mph, clear zones are still beneficial but they are to be considered only if economically feasible. <del class="diffchange diffchange-inline"> </del>Non-traversable slopes or fixed objects are to be removed, relocated or shielded by a barrier if they are within the indicated minimum clear zone width and it is cost effective to do so. <del class="diffchange diffchange-inline">Higher speeds result in vehicles traveling farther off the travelway before control is recovered. Horizontal curvature increases the likelihood of a vehicle leaving the travelway and increases the distance it travels. The designer may choose to modify the clear zone distance obtained from RDG Figure 3.1 by using [[media:231.2 Horizontal Curve Adjustments.pdf|Table 3.2]] (adjusting the values for horizontal curvature as necessary). These modifications are normally only considered where accident histories indicate a need, or a specific site investigation shows a definite accident potential which could be significantly lessened by increasing the clear zone width and such increases are cost-effective. Steeper slopes adjacent to the travelway increases the distance the vehicle travels beyond the travelway. In the implementation of the clear zone concept it is important for clear zone distances to not be used as boundaries for introducing roadside hazards such as bridge piers or trees. These are to be as far from the travelway as practical.</del></div></td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>Clear zones are <ins class="diffchange diffchange-inline">designed into a project when </ins>the anticipated posted speed of the roadway is 45 mph or more. When the anticipated posted speed is less than 45 mph, clear zones are still beneficial<ins class="diffchange diffchange-inline">, </ins>but they are to be considered only if economically feasible. Non-traversable slopes or fixed objects are to be removed<ins class="diffchange diffchange-inline">, redesigned</ins>, relocated or shielded by a barrier if they are within the indicated minimum clear zone width and it is cost effective to do so. </div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div> </div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div> </div></td></tr>
<tr><td class='diff-marker'>−</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div><del class="diffchange diffchange-inline">[[image:231.2.1 Cut Section.jpg|right|175px|thumb|<center>'''Cut Section'''</center>]]</del></div></td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>The clear zone width is to be applied with good judgment <ins class="diffchange diffchange-inline">and should </ins>be <ins class="diffchange diffchange-inline">balanced with project </ins>costs. Limited right of way or high construction costs may lead to the installation of a barrier or possibly no protection at all.</div></td></tr>
<tr><td class='diff-marker'>−</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>The clear zone width is to be applied with good judgment<del class="diffchange diffchange-inline">. If an obstacle lies just beyond the clear zone, it is to </del>be <del class="diffchange diffchange-inline">removed or shielded if </del>costs <del class="diffchange diffchange-inline">are reasonable</del>. <del class="diffchange diffchange-inline"> Conversely, the clear zone is not to be obtained at all costs. </del>Limited right of way or high construction costs may lead to the installation of a barrier or possibly no protection at all<del class="diffchange diffchange-inline">. </del></div></td><td colspan="2"> </td></tr>
<tr><td class='diff-marker'>−</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div> </div></td><td colspan="2"> </td></tr>
<tr><td class='diff-marker'>−</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div><del class="diffchange diffchange-inline">As may be noted, roadside slopes apply an important part in the clear zone width determination. Fill slopes of 1V:6H/1V:3H are preferred in areas of high fill, that is, a 1V:6H slope extending from the shoulder line out for a distance necessary to obtain the clear zone then break the slope to 1V:3H or flatter. If feasible, the flattening of slopes is preferable to installation of guardrail. In cut sections, the roadside ditch is likely to be located within the clear zone. Therefore, the configuration of the ditch and the type of [[:Category:806 Pollution, Erosion and Sediment Control|erosion control treatment]] used in the ditch must be viewed with respect to clear zone requirements. Namely, side slopes of the ditch and the method of erosion control used in the ditch must be traversable by vehicles that leave the roadway. [[media:231.2 Preferred Cross Sections for Channels with abrupt slope changes.pdf|Figure 3.6]] in the RDG is to be checked for preferred ditch cross-sections. Ditch sections must be within the shaded portions of the guides for use with clear zones. Background for this procedure is contained in Appendix A of the RDG. Any deviation from the preferred slope will be considered a special condition and is to be justified by costs or other considerations</del>.</div></td><td colspan="2"> </td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>===231.2.2 Clear Zone Perception Issues===</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>===231.2.2 Clear Zone Perception Issues===</div></td></tr>
</table>EPGsysop