Category:Minor Routes Shouldering Project Guidelines

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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.

Contents

Minimum Expectations

  • The finished roadway has a consistent 2-4 ft. wide paved shoulder.
  • 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.
  • 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 Optional Shoulder Construction JSP which gives the contractor the option to utilize either pavement type.


Corridor Consistency

  • 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).

NEPA

  • A standard RES will be submitted for each project.

Conceptual Plans

  • Shouldering jobs fall under the Federal 3R classification as defined in 23CFR 625.2(b), however.
  • 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.

Roadside Hardware

  • Guardrail that is in place but no longer needed will be removed.
  • If the height to the top of the guardrail is less than 27 3/4 in. after construction, the entire run of rail shall be replaced with new MGS.

Rumble Strips

  • On rural sections, a 12 in. rumble strip 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 strip should be milled entirely on the shoulder surface, abutting the joint.
  • Centerline rumble strips may be milled in isolated locations if the accident history reveals the need to do so, be located as specified in Std. Plan 903.02 and may be relocated by Maintenance forces or justified by design exception.

Signing

  • Signs not meeting Std Plan 903.02 may be relocated by Maintenance forces, or justified by design exception.

Drainage Structures

  • 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.

Constructability

Plans should include the Optional Shoulder Construction JSP which gives the contractor the option to utilize either pavement type.

As a best practice, grading may be quantified, estimated, and paid according to a three-tiered approach, shown below:

Grading TierDefinition Action
SimpleSufficient earth exists in situ to accommodate the entire paved shoulder Include Shoulder Grading JSP.
ModerateSome 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.
ComplexLittle to no earth exists in situ, and most material must be borrowed off R/W and compacted to accomodate the shoulderDesign conventional earthwork with excavation and compaction volumes, and cross sections.

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