We will direct your question to the appropriate person and/or agency.
Traffic Engineering Sites
Minnesota Traffic Engineering Manual Chapter 10 Section 10-2.00
Who can help
What new lighting technologies are emerging?
Answer: Contact the Traffic Engineer (Lighting Engineer) in the appropriate District to verify that the roadway is within the State's jurisdiction and for a warrant analysis (refer to the Minnesota Traffic Engineering Manual Chapter 10 - Section 10-3.01.02). If the warrant analysis does not justify the State's participation in the light installation(s) then the local agency (county or city) may apply for a utility permit (Minnesota Permit for Working on State Right-of-Way Form 172) and install the light on State right of way.
Answer: Contact the appropriate District to report repair needs or bulb outages (use the District's general phone number). Contact the Traffic Engineer (Lighting Engineer) in the appropriate District to report design issues such as light pollution or glare.
Answer: Mn/DOT needs to prioritize lighting installations considering warrants, constructions costs, maintenance costs, and utility costs. Local agencies may install lighting on Mn/DOT right of way by applying and getting approved for a utility permit.
Answer: Mn/DOT standard heights are 40 foot, 49 foot, 100 foot and 120 foot. Sometimes shorter heights are required to avoid penetration into airport air space.
Answer: Depending on the height of the pole the foundations are (steel screw in bases) 5 feet, 7 feet, (reinforced concrete) 6 feet, 9 feet, or (for the high mast lights) 6 foot T-footing with generally 3 piles at 20 feet if soil conditions are acceptable.
Answer: Mn/DOT standard bulbs are 250-watt high pressure sodium (WHPS), 400 WHPS, and 1000 WHPS. Sometimes we do use Metal Halide or test new technology.
Answer: Refer to the Minnesota DOT's Lighting Design Manual Chapter 3 for pictures and descriptions of the various types of fixtures. The types are listed as follow:
- Cobra Head Style Luminaries
- Vertical Mount
- High Mast Style
- Shoebox Style Luminaries
- Bridge Underpass Luminaries
Answer: 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."
Answer: The principal purpose of roadway lighting is to produce quick, accurate and comfortable visibility at night. The proper use of roadway lighting as an operative tool provides economic and social benefits to the public including: reduction in night accidents, aid to police protection, facilitation of traffic flow, and promotion of business and the use of public facilities during the night hours (according to the Illuminating Engineering Society (IES) of North America in Roadway Lighting RP-8-00).
Answer: Mn/DOT has been evaluating both Induction lighting and LED lighting.