Pavement markings are used to convey messages to roadway users. They indicate which part of the road to use, provide information about conditions ahead, and indicate where passing is allowed. Yellow lines separate traffic flowing in opposite directions. Drivers should stay to the right of yellow lines. A solid yellow line indicates that passing is prohibited. A dashed yellow line indicates that passing is allowed. White lines separate lanes for which travel is in the same direction. A double white line indicates that lane changes are prohibited. A single white line indicates that lane changes are discouraged. A dashed white line indicates that lane changes are allowed.
Symbols are used to indicate permitted lane usages. A diamond indicates a lane reserved for use by high-occupancy vehicles. A bicycle indicates a lane reserved for bicyclists. Arrows show required or permitted movements at intersections. A row of solid triangles indicates that the road user must yield.
Pavement markings are also used to alert users to potentially hazardous conditions ahead. A letter X with a letter R on each side indicates a highway-rail grade crossing ahead. A hollow triangle indicates a yield ahead. A series of progressively wider lines across a lane indicates a speed hump ahead.
Standards for the design and application of pavement markings can be found in the Manual on Uniform Traffic Control Devices (MUTCD). Design specifications for pavement markings are in the Standard Highway Signs Book. Both of these books are available online at http://mutcd.fhwa.dot.gov. The MUTCD is also available for purchase through the American Association of State Highway and Transportation Officials (http://www.aashto.org), the Institute of Transportation Engineers (http://www.ite.org), the American Traffic Safety Services Association (http://www.atssa.com), and the U.S. Government Printing office (http://www.gpo.gov). The Standards Highway Signs Book can be purchased from the U.S. Government Printing Office and the American Traffic Safety Services Association.
Prepared in 2002 by the
U.S. Department of Transportation
Federal Highway Administration
Office of Transportation Operations
United States Department of Transportation - Federal Highway Administration