Michigan’s winter maintenance vehicles getting green lights to improve visibility


New green flashing lights are being incorporated on winter maintenance vehicles in Michigan this winter, but rather than indicating ‘Go’ or ‘All Clear’, in this case, green means ‘Slow Down’.

In an effort to reduce crashes on its road network, the Michigan Department of Transportation (MDOT), together with some 50 Michigan county road commissions and several municipalities, will be using green and amber lights that may be flashing, rotating or oscillating on their winter maintenance vehicles. Studies suggest that humans can differentiate more shades of green than any other color. Experts say that blue is the preferred and most visible color, but is reserved for emergency vehicles. Green has the closest wavelength and is a suitable alternative. Better visibility with green lights means safer roads for winter maintenance workers and motorists.

The Kent County Road Commission (KCRC) has been piloting the green lights for the past two years with great success, and the County Road Association of Michigan supports and has helped push for the enabling legislation.

The wider use of the green lights is a result of legislation sponsored by Rep Rob VerHeulen that amends the Michigan Vehicle Code to allow for the use of the color green on maintenance vehicles. As the lights on winter maintenance trucks are replaced, the new green lenses are being incorporated. A combination of green and amber lights, which can be flashing, rotating or oscillating, can be used by state, county, or municipal agencies responsible for winter or maintenance operations. Approximately 70% of Michigan’s 83 county road commissions will use green lights on their trucks this year.

“Our visual system would be more attracted to a bright green light versus a bright white flashing light in a heavy snowstorm,” explained Dr Bernie Tekiele of the Michigan Eye Institute. “Our visual system is piqued to be sensitive to the green/yellow spectrum.”

Jerry Byrne, deputy managing director of KCRC, noted, “We haven’t had any rear-end accidents with the green lights on the trucks that we’ve had for the past two years, and that’s what we’re really trying to eliminate. Folks slow down and don’t rear-end the backs of the trucks. We’ve had injury incidents in the past, so our goal is to spend a little money to save the number of accidents.”

Mark Geib, engineer in MDOT’s operations field services, commented, “The cost, really, to the state is just the lens on the back of a light. It’s small. Something less than US$100 per truck. So, since we put lights on anyway, in time there’s really going to be no additional cost to speak of.”

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Tom has edited Traffic Technology International (TTi) magazine and its Traffic Technology Today website since May 2014. During his time at the title, he has interviewed some of the top transportation chiefs at public agencies around the world as well as CEOs of leading multinationals and ground-breaking start-ups. Tom's earlier career saw him working on some the UK's leading consumer magazine titles. He has a law degree from the London School of Economics (LSE).