Category:Minor Routes Shouldering Project Guidelines
Shoulders of any width provide the proven safety benefit of extra recovery area for errant vehicles. The public perceives shoulders as an enhancement to the transportation system and have consistently identified them as a top tier desire. In response, MoDOT has challenged their districts to assemble funding from any source possible and provide as many miles of shoulders on its minor routes as possible. The following guidelines are offered as an aid to facilitate the design of these projects.
- The finished roadway has a consistent 2-4 ft. wide paved shoulder.
- Edgeline rumble stripes are provided.
- No right of way is acquired except in unique, isolated circumstances.
- Ditches, however altered, will flow properly.
- A Safety EdgeSM will be constructed at the edge of each 4 ft. wide or narrower shoulder.
- The traveled way should be overlaid with a 1 in. level course flush with the finished shoulder surface.
- Districts will collaborate on corridors that cross district lines.
- Corridors will have logical termini.
- In general, shoulder improvements should appear the same (to the public).
- A standard RES will be submitted for each project.
- All projects will be classified as Categorical Exclusions (CE).
- Shouldering jobs fall under the Federal 3R classification as defined in 23CFR 625.2(b), however.
- A conventional Conceptual Study Report, instead of 3R, will be prepared.
- The appropriate rural and urban 3R standards will apply to design.
- Where 3R standards cannot be met, design exceptions will be submitted on a corridor-wide basis.
- The Highway Safety Manual (HSM) analysis required of design exceptions may be waived given the narrowly focused scope of shouldering.
- All blunt ends, turned-down ends, and BCTs will be replaced with crashworthy end terminals.
- The length of need (LON) need not be adjusted unless accident history or district policy presents the need to do so.
- Guardrail that is in place but no longer needed will be removed.
- If the height to the top of the guardrail is less than 26 ½ in. after construction, it should be increased to 29 inches. If the rail adjustment cannot be accommodated within the scope of the project, a design exception must be executed.
- On rural sections, a 12 in. rumble stripe should be milled straddling the line between shoulder and traveled way.
- In the event that the traveled way has not been overlaid, a 12 in. rumble stripe should be milled entirely on the shoulder surface, abutting the joint.
- Centerline rumble stripes may be milled in isolated locations if the accident history reveals the need to do so.
- Signs should be located as specified in Std. Plan 903.02.
- Signs not meeting Std Plan 903.02 may be relocated by Maintenance forces, or justified by design exception.
- A 2 ft. minimum width shoulder will be provided over all pipes 36 in. or less in diameter. To accomplish this,
- Pipes may be extended, or
- Slopes may be warped within reason.
- Shoulders may be narrowed or discontinued over box culverts and pipes over 36 in. in diameter.
Plans should include the Modified Shoulder Construction JSP which gives the contractor the option to pave the mainline and build the shoulders monolithically. The pavement team will determine if this method is applicable for areas of poor subgrade or shoulder widths wider than 2 feet.
As a best practice, grading may be quantified, estimated, and paid according to a three-tiered approach, shown below:
|Simple||Sufficient earth exists in situ to accommodate the entire paved shoulder||Include Shoulder Grading JSP.|
|Moderate||Some earth exists in situ, but additional material, generally from within the R/W, must be placed to accomodate the shoulder||Include Shoulder Grading JSP and include earthwork volumes for information only.|
|Complex||Little to no earth exists in situ, and most material must be borrowed off R/W and compacted to accomodate the shoulder||Design conventional earthwork with excavation and compaction volumes, and cross sections.|