In rural areas or other sites where flush shoulders approach a bridge and light pedestrian traffic is anticipated on the shoulders, the shoulder width should be continued across the bridge and possibly even increased to account for the restriction to pedestrian escape imposed by the bridge rail. A flush roadway shoulder should never be interrupted by a raised walkway or a bridge. On long bridges, if accommodation of pedestrian traffic is considered essential, a single walkway may be provided. However, care must be taken to ensure that approach walkways provide safe and relatively direct access to the bridge walkway. This may require the erection of fences to channelize the pedestrians and prevent or control pedestrian conflicts with vehicular traffic.
Shoulders are desirable on any highway, and urban arterials are no exception.
They contribute to safety by affording maneuver room and providing space for immobilized vehicles. They offer a measure of safety to the occasional pedestrian in sparsely developed areas where sidewalks are not appropriate and provide space for bicyclists. They serve as speed-change lanes for vehicles turning into driveways, and they provide storage space for plowed snow. Where the abutting property is used for commercial purposes or consists of high-density residential development, a shoulder, if provided, is subject to such heavy use in serving local traffic that the pavement strength must be about the same as that for the travel lanes. In addition, a raised curb at the outer edge of the shoulder is usually necessary in heavily developed areas as a means of controlling access and preventing deterioration of the shoulder.