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FHWA Home / Safety / Intersection / Embedded LEDs in Signs

Embedded LEDs in Signs

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May 2009


Embedded Light Emitting Diodes (LED) in sign faces improve safety at intersections by enhancing driver awareness of traffic-control signs.

Alternative Names

Solar-powered LED road signs, flashing LED-enhanced solar-powered traffic signs, LED-enhanced signs.

This summary is one in a series describing Innovative Intersection Safety Treatments. The summaries identify new technologies and techniques to improve intersection safety developed since NCHRP Report 500, Volumes 5 and 12, were published in 2003 and 2004, respectively. These treatments show promise for improving safety but comprehensive effectiveness evaluations are not yet available.


LEDs can be embedded in standard highway warning and regulatory signs to outline either the sign itself or the words and symbols on the sign. The LEDs may be set to flash or operate in steady mode. LEDs may be illuminated 24 hours a day, or be activated by vehicles or pedestrians. Due to the low power requirements of LEDs, signs with embedded LEDs can typically be powered using stand-alone solar panel units.

This treatment is applicable for regulatory and warning signs at unsignalized intersections with the intended purpose of improving the visual conspicuity of the signs. Typical locations where LED-embedded signs can be implemented include:

Potential Benefits

In general, embedded LED units are used to:

Agency Experience

Figure 1: Example of stop sign with embedded LEDs around the rim of the octagonal sign and a solar unit mounted above.
Figure 2: LEDs are embedded in the symbols and lettering on a truck warning sign.
Figure 3: Example of pedestrian crossing warning sign with embedded LEDs and solar unit. Sign features a pedestrian on a yellow background with LED lights embedded around the rim of the sign and a solar unit mounted above it.

A study on safety effects of LEDs embedded in STOP signs, conducted by the Texas Transportation Institute in 2004, found:

A similar study, conducted by the Virginia Transportation Research Council in 2007, found:

LED lights have been used in signs in Florida and Wisconsin and have been evaluated in STOP signs in Virginia and Texas. Naval Station Mayport in Florida installed a pedestrian walk sign with embedded LEDs.

Implementation Considerations

Manual on Uniform Traffic Control Devices (MUTCD) Specifications


During the course of the 2007 Virginia Transportation Research Council study, the costs for 48-inch, 36-inch, and 30-inch signs embedded with LEDs were estimated at $1,860, $1,640, and $1,600, respectively. This included the cost of the solar power supply, but did not include an additional $175 for post and anchor or the cost of installation.

Learn More

Michael Winn, Virginia DOT

Ed Rice, Intersection Safety Team Leader FHWA
Office of Safety

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Page last modified on April 1, 2019
Safe Roads for a Safer Future - Investment in roadway safety saves lives
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