Transportation Studies

ADOT LED Lighting Pilot Study

LED LightThe Arizona Department of Transportation (ADOT) is conducting a pilot program to study lighting and the effects of converting the current lighting system from High Pressure Sodium (HPS) to Light Emitting Diode (LED). 

The goal of the pilot program is to better evaluate potential energy savings, cost savings, operation of the system and impacts of an LED upgrade. 

Studies have found the whiter light common to LED roadway lighting may result in better driver reaction times and improved visibility.  An additional safety benefit is the longer life of the light, requiring less maintenance and crews working along the freeways. 

LED lighting will also have positive environmental impacts given the following:

  • *Existing carbon footprint of the HPS system = 33.7 tons per year
  • Expected new carbon footprint of LED lighting = 13.1 tons per year
  • Expected annual carbon reduction:  (33.7 – 13.1) = 20.6 tons per year,  a carbon reduction of approximately 60%.


As part of the pilot program, ADOT intends to convert 36 light fixtures located along the Loop 202 (Santan Freeway) approximately one half mile on either side of Recker Road.  This location was selected for the pilot because of earlier studies related to energy use and costs performed for this site and the consistency in the type of fixtures in this one mile of roadway.

ADOT made the conversion from HPS to LED the week of September 5th, 2016 and will continue to monitor until late 2017”.  After this period of data collection, a detailed analysis will reflect actual and predictable cost savings from the conversion, in addition to the effective rate, power consumption and overall system operability. 

If you have any questions about the pilot or lighting systems, please contact, or call 855.712.8530. 

LED Lighting Project Example Comparison

LED Lighting Project Example Comparison

View information about ADOT’s LED Lighting Project in the Maricopa County region.
Arizona State Logo - Official Website of the State of Arizona

 ADOT Logo

Arizona Department of Transportation

Contact Us

Join the ADOT Team - Employment Opportunities