it is also a law here in Michigan but one that many people choose to ignore- guess they don't care if other's see them coming...personally - i always have my head lights on if driving down the road- i definitly want the other cars to see me coming- accidents suck!
here the law is- if the weather is (inclimate), you need windshield wipers- if is foggy- visibility is 1 mile or less- headlights are supposed to be on- so many people just don't (bother) but then wonder why they were not seen when they get run into- in our family we make it a pretty strict rule- if you want to pull out of the driveway-the head lights are on- seat belt is buckled- mirrors and seats are adjusted to fit you---no exceptions-