Most passenger cars in Michigan, Indiana and Illinois never go through a periodic safety inspection, so there is no annual inspection for a crack to fail. A crack still matters on the road, at the dealership and for commercial vehicles.
Passenger cars
Michigan, Indiana and Illinois do not require a routine safety inspection for most passenger cars. Illinois emissions testing in the Chicago and Metro East areas checks emissions, not the glass. What does apply is each state’s equipment law: driving with glass that blocks your view can get you stopped. See the cracked windshield laws for each state.
Commercial trucks
Commercial motor vehicles are held to the federal windshield standard in 49 CFR 393.60, which limits cracks and chips in the area swept by the wipers. A crack there can be written up at a roadside inspection. Illinois also requires safety tests for some trucks and buses.
Selling or returning a leased car
A lease-end or trade-in inspection often counts windshield damage against the vehicle’s condition. Repairing a chip before it spreads, or replacing a cracked windshield with OEM or OEM-equivalent glass matched to the VIN, keeps that from coming off your value.
Moving to another state
Some states do inspect windshields. If you are moving and will register the car somewhere else, check that state’s rules before your appointment.