Begin Main Content Area

Light-Emitting Diode (LED) Highway Lighting and Policy

highway at night with streetlights using LED bulbs

LED lighting has an estimated life span of 20 years with a 10-year manufacturer guarantee. The innovation's pilot project used LED lights on the Clarks Ferry Bridge, carrying US 22/322 over the Susquehanna River, in Reed Township, Dauphin County. Since then, LEDs have been used on bridges across the state including several in the Harrisburg area. LED luminaires are now being used across the industry, as HPS bulbs are being produced less by manufacturers.

How Does It Work?

The Maintenance TAG evaluated the use of LED highway lighting bulbs over traditional high-pressure sodium (HPS) lighting bulbs, and promoted the use of LED luminaires on highways and bridges across Pennsylvania. This effort will give highway lighting designers another option to choose when scoping their projects for efficiencies, motorist safety, and community needs. The Maintenance TAG's work incorporates LED highway lighting specifications into Publication 408 (PDF), PennDOT's current construction specifications. The Maintenance TAG was also able to get a lighting manufacturer approved in Bulletin 15 for future highway/bridge projects and local municipalities use.

What Are The Benefits?

Initial estimates show that overall cost efficiency of LED lights is about 30 percent when compared to traditional HPS bulbs. HPS bulbs need to be changed and cleaned every three years, with the maintenance of LED lights only requiring lens cleaning with no cyclical replacement. LED and HPS lights cast the same amount of light; the difference between the two is in the color of the light. LEDs cast a white light that appears brighter to motorists than the orange light cast by HPS bulbs. LED lights also better penetrate fog.

DID YOU KNOW... LED lights are also used in traffic signals? PennDOT's Green Light-Go program awards up to $40 million annually for traffic light improvements to local municipalities and planning organizations — LED replacement being one of them.