Vehicle warning lights

The Michigan DOT has not conducted specific research regarding vehicle warning light effectiveness.
Rotating halogen, strobe, and LED vehicle warning lights are allowed on DOT vehicles.
The following documents address the types of vehicles that Michigan DOT requires to use warning lights:
— S&P2741-1.pdf
— S&P2741-2.pdf
The department has not encountered any difficulties in the types of warning lights uesd.
The department does not track the age and effectiveness of lights on state-owned vehicles.
The department requires warning lights for private contractor vehicles in work zones when working near or on an active traveled roadway.
The department does not have any specific language regarding specifications for vehicle warning light use. Each purchaser uses his or her own discretion.
LED lights can be the sole warning light on vehicles.