Minnesota Department of Transportation

511 Travel Info

Traffic Engineering

traffic engineering workers

Lighting facts

  • MnDOT uses Light Emitting Diode (LED) luminaires as a standard light source for the majority of our roadway lighting. High Pressure Sodium (HPS) luminaires have been replaced throughout the state with LED luminaires and will continue to be replaced as funding becomes available.
  • MnDOT prioritizes roadway lighting installations considering warrants, construction costs, maintenance costs, and utility costs. Local agencies may install lighting on MnDOT right of way by applying and getting approved for a utility permit.
  • MnDOT standard pole heights are 40 foot and 49 foot. High Mast Tower Lighting poles are 100 foot, 120 foot and 140 foot. Sometimes shorter heights are required to avoid penetration into airport air space.
  • Depending on the height of the pole, the concrete foundations are between a minimum of 6 feet and 9 feet deep with the option of using a steel screw in foundation. The depth of the high mast foundations will vary based on soil conditions, but typically consist of 3 piles at no less than 20 feet deep.
  • Objects within a "clear zone" need to either have guardrail or be "breakaway". If there is not guardrail around an object it is either "breakaway" or outside the "clear zone."
For more technical information on traffic lighting design or operation on MnDOT projects contact:

Sue Zarling