Address Visual Traps with Pavement Markings

Image Source: Google Earth – Louisville, KY

DEFINITION AND DESCRIPTION

Pavement edge lines typically discontinue in areas such as intersections and large, commercial entrances.  Offset, skewed, complex, or multi-leg intersections, on curved roadways, may create “visual traps” and cause driver confusion.  Multiple or offset left-turn lanes may also benefit from channelization to guide the driver. Dotted lane line extensions and edge lines can be used through intersections.

Implementation Categories

CONSIDERATIONS

• Consult the MUTCD Section 3B.11 for more information on applications.
• TO-504 includes guidance on dotted lane line extensions.  They are required for multiple turn lanes through the intersection.
• The TPM series Standard Drawings include typical pavement markings. Crosshatching may be used in areas at least 6 ft wide.
• Dotted lane line extensions markings consist of 2 ft line segments and 2-6 ft gaps.  The MUTCD allows for solid lane lines or channelizing lines to extend into or through an intersection where greater restriction is preferred.

APPLICATION

• Develop pavement marking recommendations for “visual traps”.  Consider intersection geometry, curvature, width of entrances, and intersection tapers.  Also consider temporary pavement markings in work zones.  
• Pavement marking details or plans abating the visual traps should be provided to:
  • • Maintenance prior to resurfacing
    • Construction for applicable phases of traffic control
    • Project development teams for permanent markings on capital improvement projects 

example

Image Source: Google Earth

Complimentary Countermeasures

• Human Factors Guidance – Countermeasures to Improve Pavement Delineation