When To Use Your Lights & Blinkers


Modern vehicles are equipped with a variety of lights designed to help drivers see the road and announce their intentions, but misuse or lack of use can leave other motorists in the dark.

Last month, I asked Traffic Talk readers to describe what frustrates them most about their fellow drivers. Several readers responded with questions or complaints about headlights, high beams and blinkers.

“I wish everyone would use their headlights whenever conditions limit visiblity, such as dusk, snow, rain and fog!” wrote one driver. “That would truly be defensive driving. Sometimes I can only hope that it is safe to turn onto another street because I don’t see any headlights, only to find I nearly hit somebody who didn’t have headlights on.”

Michigan law requires motorists to use their headlights from a half hour after sunset to a half hour before sunrise and “at any other times when there is not sufficient light to render clearly discernible persons and vehicles on the highway at a distance of 500 feet ahead.”

The law allows for extra time after sunset because the road remains visible during twilight, according to Sgt. Mike Church, a traffic code expert with the Michigan State Police.

Last year, Democratic State Rep. George Darany of Dearborn introduced legislation seeking to require motorists to use their headlights when driving in any form of precipitation, but the bill has not advanced past committee.

Current Michigan law “doesn’t specify anything about rain or snow,” Church said, “but if it’s too dark because of those conditions then you must use headlights.”

When headlights aren’t bright enough, many motorist will use their high beams on poorly-lit roads, and some even use them to send signals to other drivers.

Richard Wagonlander of Flushing said he likes to use the “flash” feature on his high beam control arm to alert a driver traveling too slowly in the passing lane.

“By flashing them they would move to (the) right, if safe, and let you pass them,” he wrote. “No one, but me, seems to use the feature and cars do not move over anyway.”

Michigan law prevents motorists from using high beams when there is an oncoming vehicle within 500 feet, but in the absence of approaching traffic, nothing in the law specifically prevents drivers from flashing vehicles that are travelling in the same direction.

That said, some feel that flashing to pass is rude, and a guide published by the Michigan Secretary of State advises motorists never to use high beams when travelling behind another vehicle, citing the potential for distractions.

A few readers said they were frustrated by their fellow motorists who drive all day long with their fog lights on. Michigan law doesn’t prevent such behavior, Church said, but it does prohibit the use of bright lights aimed so that “the glaring rays” are projected into the eyes of an oncoming driver who is less than 500 feet away.

Several readers also criticized fellow motorists who either drive overly-long distances with their blinker on (perhaps obliviously) or only apply their blinker after they have already started their turn.

Michigan law clearly requires drivers to use a signal — either a blinker or an arm gesture — before turning, but it does not specify how far in advance they must do so.

Church pointed to case law going back to at least 1958 requiring motorists to use an “intelligible” signal to warn vehicles approaching from the rear.

“‘Intelligible’ is obviously subjective and fact specific,” he said. “I have seen driver’s education materials that give a specific distance to signal before turning, but that isn’t in the law. And the problem is that roadways vary. What may be an appropriate distance on a 55 mph country road might not be appropriate in a 25 mph zone that has a driveway every 50 feet.”

Bottom line: Use your headlights when it’s dark, your high beams only in the absence of oncoming traffic and your blinker before you turn.