ROCKFORD, Ill. (WTVO) — Hypothetically, if you get a flat tire and you’re only a mile away from the nearest service station — and you don’t have a spare tire — do you call a tow truck? Or drive on the flat?

According to Illinois law, you call the tow truck.

It is illegal in the state to drive on a flat tire, which is considered unsafe.

According to the Illinois Vehicle Code (625 ILCS 5/12-405), “No person or organization shall place, drive or move, or cause or allow to be placed, driven or moved, on a highway of this State, any vehicle equipped with one or more pneumatic tires deemed to be unsafe.”

However, there are exceptions, but those are in effect only if the vehicle is being transported “not under its own power,” such as being towed, pushed “or otherwise transferred” to a repair, relocation, storage, salvage, junking, or another collection site.

Illinois law considers a tire unsafe if the tread or sidewall is cracked; if there is a bulge or knot; or if the tread wear indicators are less than 4/32 of an inch (on a vehicle other than a motorcycle or truck).

Some cars are equipped with spare tires for this specific purpose. Newer cars sometimes come with self-sealing or run-flat tires that will give owners a short amount of drive time in order to get the vehicle to the nearest service center.