Shoulder (road)

A shoulder, often serving as an emergency stopping lane, is a reserved lane by the verge of a road or motorway, on the right in countries which drive on the right, or on the left side in Japan, the UK, Australia, and other left-side driving countries. Many wider U.S. freeways have shoulders on both sides of each directional carriageway, in the median as well as at the outer edges of the road, for additional safety. Typically the shoulder is not for use by moving traffic.

Shoulders have multiple uses, including:


 * In the event of an emergency or breakdown, a motorist can pull into the shoulder to get out of the flow of traffic and obtain a greater degree of safety.
 * Emergency vehicles such as ambulances and police cars may use the shoulder to bypass traffic congestion.
 * Active traffic management, used on busy multi-lane roads, may allow 'hard shoulder running' by general traffic at reduced speeds during periods of high traffic volumes.
 * In some places a 'Bus bypass shoulder' may be provided which allows bus services to pass stationary traffic.
 * Paved shoulders provide additional space should a motorist need to take evasive action (such as avoiding a wrong-way driver) or need to recover control of their vehicle before a run-off-road collision occurs.
 * In some urban areas, shoulders are used as travel lanes during peak commuting hours.
 * In some rural areas without sidewalks, pedestrians and cyclists may be allowed to walk or ride on the shoulders.
 * On curbed roadways, shoulders move the gutter away from the travel lanes which reduces the risk of hydroplaning, and reduces splash and spray of stormwater onto pedestrians using any adjacent sidewalk.
 * Paved shoulders move water away from the roadway before it can infiltrate into the road's subbase, increasing the life expectancy of the road surface.
 * Shoulders help provide extra structural support of the roadway.