MUTCD is a compilation of the national standards for traffic control devices, including road signs, traffic signals and MUTCD pavement markings which provide information and guidance for the road users. Pavement markings are either used alone or to supplement other traffic devices, such as signs and signals. Other road markings that are also used include delineators, barricades, object markers, colored pavements and channelizing devices.
Although pavement markings are effective in conveying traffic regulations, guidance, and warnings, their visibility is always limited during certain weather conditions by debris, water, and snow. They are also easily affected by roads that experience heavy traffic depending on the strength of the material that is used.
Despite the limitations, markings enhance road delineation, while also posing minimum diversion of attention to the road users.
Pavement markings convey to road users which part of the road to use, the condition of the road ahead, and indicate where passing is allowed and where it is prohibited. This is done using lines, symbols and letters whose standards for the design and application are found in the MUTCD.
The main pavement markings involve the use of either continuous or dashed yellow and white lines. Yellow lines separate traffic that is moving in opposite directions while white lines separate traffic that is moving in the same direction. Dashed lines allow passing or lane changes while solid lines do not.
Symbols that are used in pavement markings include: arrows at intersections that show permitted or prohibited movements, white diamond symbols indicating lanes to be used by heavy vehicles, bicycles indicating a reserved lane for bicycles, and a row of solid triangles indicating a road user must yield at the non-signaled crosswalk. Other pavement markings include a hollow triangle that indicates there is a yield ahead, a letter X with letter R on each side which indicates a highway-grade rail crossing ahead. If you see a series of wide progressive lines, they are speed bump ahead indicators.
MUTCD pavement markings are used at freeway entrances and exits, HOV lanes, intersections, two-way traffic lanes, work zone lanes and other miscellaneous lanes. They should be in place before any road (whether permanent or temporary) is opened to traffic. Also, they should be clearly visible despite the time of day and not capable of confusing road users.