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FHWA Safety: First graphic from left courtesy of (http://www.pedbikeimages.org/Dan Burden)
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Nighttime Visibility

vehicles in traffic at night

Nighttime visibility of signs and pavement markings provide critical information to drivers at night, help drivers navigate the road during nighttime hours, enhance traffic flow and driver mobility, and promotes safe driving.

Retroreflectivity is the scientific term that describes the ability of a surface to return light back to its source. Retroreflective signs and pavement markings bounce light from vehicle headlights back toward the vehicle and the driver's eyes, making signs and pavement markings visible to the driver.

Signs

  • Announcement of Final Rule: Revision 2 of the 2003 Manual on Uniform Traffic Control Devices (MUTCD) was published in the Federal Register on December 21, 2007, and is effective as of January 22, 2008. The final rule provides additional requirements, guidance, clarification, and flexibility in maintaining traffic sign retroreflectivity that is already required by the MUTCD. The minimum retroreflectivity levels and maintenance methods consider changes in the composition of the vehicle population, vehicle headlamp design, and the demographics of drivers. The FHWA expects that the levels and maintenance methods will help to promote safety and mobility on the nation’s streets and highways.
  • Other Sign Retroreflectivity Information:

Pavement Markings

Photo of pavement markings

The FHWA has prepared updated background information regarding pavement marking retroreflectivty:

Manual on Uniform Traffic Control Devices (MUTCD)

Retroreflectivity General Information

'Know Your Retro' displayed on a yellow sign

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