Markings on public and private roads open to public travel have important functions in providing guidance and information for the road user.
Major types of pavement markings include: lane striping, painted medians/islands, bike lane symbols, crosswalks and stop bars. In some cases, markings are used to supplement other traffic control devices such as signs and signals. In other instances, markings are used alone to effectively convey regulations, or provide guidance or warnings.
Visibility of pavement markings can be limited by snow, dirt and debris, as well as water on or adjacent to the markings. These factors can either cover up the pavement markings, or skew their visibility during both daytime and nighttime.
Marking durability is affected by several variables including material characteristics, traffic volumes, weather, and location. Some materials are meant to last longer than others in our climate. Traffic driving over pavement markings slowly degrades and destroys the markings. Therefore, streets that have more traffic tend to have a more durable material used for pavement markings. In addition, under most highway conditions, markings provide important information while allowing minimal diversion of attention from the roadway.
When used, white markings for lengthwise lines shall indicate:
- The separation of traffic flows in the same direction, or
- The right-hand edge of the roadway.
When used, yellow markings for lengthwise lines shall delineate:
- The separation of traffic traveling in opposite directions;
- The left-hand edge of the roadways of divided highways and one-way streets or ramps; or
- The separation of two-way left-turn lanes and reversible lanes from other lanes.
Crosswalk Striping and Stop Bar Striping
Crosswalk markings provide guidance for pedestrians who are crossing roadways by defining and delineating paths on approaches to and within signalized intersections, and on approaches to other intersections where traffic stops. In conjunction with signs and other devices, crosswalk markings help to alert drivers of a pedestrian crossing point across roadways that are not controlled by traffic control signals or STOP or YIELD signs. At intersection and non-intersection locations, crosswalk markings legally establish the crosswalk. Additionally, drivers who yield too close to the crosswalks on multi-lane approaches place pedestrians at risk by blocking the view of other drivers to see pedestrians and they also block the pedestrians view of other vehicles.
Stop bars are the thick, transverse white lines which extend across lanes to indicate the point at which vehicles should stop either at an intersection or for some other traffic control device. The stop bars serve as the barrier for entering an intersection, and also provide the location for the vehicle to be detected by a traffic signal loop, video camera, or radar detector. If a vehicle pulls past the stop bar, it may not be detected.