WSDOT Traffic Manual M 51-02.10 Page 3-1
May 2021
Chapter 3 Delineation and Markings
3-1 General
Delineation is the pavement markings, guideposts, and raised pavement markers used on
and adjacent to the roadway to define vehicular travel paths. The MUTCD, Design Manual,
and Standard Plans provide delineation placement guidelines.
The Roadway Delineation Practices Handbook, published by FHWA, discusses specialized
materials and delineation treatments for unique applications and situations. This handbook
does not establish policies or standards but is only a reference document.
3-2 Pavement Markings
Pavement markings are classified as either longitudinal or transverse. Materials typically
used for each are paint for longitudinal markings and durables for transverse markings.
Durable markings include thermoplastics, Meythl Methacrylate, tape, etc. Durable markings
are generally used in locations with higher ADT, high truck traffic and/or areas with
increased turning radius. Approved sources for durable materials are listed in the General
Special Provisions. A purchase contract is available for the purchase of paint. New durable
materials are continually being evaluated.
A. Intersection Channelization – The MUTCD has a provision that allows pavement
markings to be extended through an intersection where design or visibility conditions
make it desirable to provide control through the intersection. These markings are
only installed as the result of a traffic engineering analysis that considers horizontal
curvature and other visibility conditions. For statewide uniformity, the dotted line used
for this extension is applied as a 2-foot stripe with a 4-foot gap between stripes.
Multilane approaches may provide exclusive or shared lanes for turning and through
vehicles. At most intersections through traffic must share a lane with one direction of
turning traffic. To minimize delay, through traffic should normally be combined with
right-turning traffic unless opposite approach geometrics are unfavorable. An offset
centerline and minor widening may help accomplish the proper lane assignments.
Stop lines can be included at signalized intersections with crosswalks but are to be
included at signalized intersections without crosswalks. At nonsignalized intersections,
stop lines are necessary on the stop sign control approaches when crosswalks are
not included. Including the stop line at stop sign control locations having marked
crosswalks is optional.
