High-Mast LEDs Cast Plenty of Light on Highway


The goal of an Idaho highway lighting project was to light a new interstate interchange with LED fixtures and utilize high-mast poles to minimize the number of poles needed in the design.

State officials were already familiar with the benefits of LED lighting, having used LEDs on previous interchange projects around the state, but using LED fixtures in combination with high-mast poles was uncharted territory.

The state chose LED fixtures for its Chubbuck, Idaho, project. Cooper Lighting worked with state officials to install LED luminaires, which provide the required high lumen output and distribution for the 80-foot installation. The luminaires also met the need to match the color temperature of existing LED fixtures on surrounding roadways, and they offered improved energy efficiency.

There are three major benefits from the LED lights: reduced power usage while still maintaining similar light levels, a much higher color rendering index (CRI) and longer time frames between required maintenance.

  1. The four LED fixtures mounted on each pole consume 1,140 watts, versus 1,872 watts, a reduction of 732 watts or 39 percent.
  2. The LED luminaire has a much higher CRI of 70, versus the traditional high-pressure sodium (HPS) fixture with only a 20 CRI.
  3. HPS fixtures are rated for 24,000 hours or approximately 5.5 years before complete failure of the lamp and because of this they are relamped on a three to four year schedule. The LED fixture is rated for 60,000 hours of life. This allows the potential to extend the luminaire maintenance intervals by more than three times their current rate – replacing current three to four year cycles with up to a 14 to 16 year intervals.

Since this application represented a first in the use of LED fixtures in high-mast lighting, state officials needed to ensure that the product would provide proper illumination compared to the HPS alternatives, and so a field test site was created at a nearby rest area. This site allowed for an easy comparison of the light output and distribution between 100-foot high-mast poles with 400-watt HPS fixtures and those with the 285-watt LED fixtures.

1 reply
  1. Ron Jewett
    Ron Jewett says:

    At Raleigh-Durham Int’l we need to replace 90 HPS lights with LEDs (5 lights on 18 one hundred feet tall high mast poles). I need a budget number for the conversion to prepare for next year. Can you advise? Thnx


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