Roadways: Paved Shoulders

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Paved Shoulders

Primary Guidance

  • Consider shoulder paving width
  • The MDOTMaryland Department of Transportation’s SHA Office of Materials Technology (OMT) will approve the pavement thickness for all projects on State highways
  • ShoulderThe portion of the roadbed contiguous with the traveled way for accommodation of stopped vehicles, for emergency use, and for lateral support of base and surface courses. pavement depth design will be based on 10 percent of the mainline Average Daily Truck Traffic (ADTT) . Exceptions are:
    • ShoulderThe portion of the roadbed contiguous with the traveled way for accommodation of stopped vehicles, for emergency use, and for lateral support of base and surface courses. pavement type can match the mainline surface if it is the most cost effective solution
    • When drainage issues are or are likely to be present

(Consideration should be given to match the mainline roadway overall pavement thickness [asphalt/concrete + aggregate base] by increasing the aggregate thickness to match the bottom of the roadway aggregate)

  • Any auxiliary, acceleration, deceleration, and ramp lanes directly adjacent to mainline pavement shall be considered to be part of the mainline pavement until those lanes split off at the gore area
  • Permeable pavements may be considered where significant right-of-way or other stormwater management (SWMStormwater Management) costs exist
  • Permeable pavements shall not be used where the speed limit will be greater than 35mph

Discussion

Paved shoulders and aggregate stabilized shoulders provide a secure surface to accommodate vehicles for emergencies and other uses. Paved shoulders are an integral part of the pavement structure and considered part of the pavement design configuration. The lead design office will decide the overall width of the paved shoulder. For maintenance, structural, or safety concerns, a 2 ft. minimum paved shoulder should be provided directly adjacent to traveled way.

ShoulderThe portion of the roadbed contiguous with the traveled way for accommodation of stopped vehicles, for emergency use, and for lateral support of base and surface courses. pavement will not be designed to be the same thickness as mainline roadway. Except for the following exceptions, shoulder pavement design will be based on 10 percent of the mainline Average Daily Truck Traffic (ADTT) :

  • BridgeA structure including supports erected over a depression or an obstruction, such as water, highway, or railway, and having a track or passageway for carrying traffic or other moving loads, and having an opening measured along the center of the roadway of more than 20 feet between undercopings of abutments or spring lines of arches, or extreme ends of openings for multiple boxes; it may also include multiple pipes, where the clear distance between openings is less than half of the smaller contiguous opening. For lengths, all dimensions shall be parallel to the center line of the roadway. The dimensions of handrails will not be taken into account in measuring bridge lengths. Any bridge or highway grade separation structure includes the connecting highways, substructure, superstructure, roadway approaches, entrance plazas, interchanges, overpasses, underpasses, and other structures which the Administration may deem necessary together with all property rights, easements, franchises, and interests acquired by the Administration for the construction and operation of the bridge. Approaches, within 500 ft. of bridge
  • Intersections, within 500 ft. of intersection
  • Shoulders less than 6 ft. wide

There is a significant likelihood that shoulders will be used for Maintenance of Traffic (MOT) at bridge approaches and converted to turn lanes at intersections. When less than 6 ft. wide, it is impractical to construct shoulders in a separate pass from the mainline. Where an additional lane is considered imminent, the shoulder should be designed for 100 percent traffic, with the width desired for future lane use. RampA connecting roadway between two intersecting highways at a highway separation. shoulders should be consistent with the mainline.

Permeable pavements should only be considered in areas where the underlying subgrade drainage is good (typically sandy material), and provisions for routine maintenance must be made.


See Also