Headway
Headway of motor vehicles, generally - 158.

(1) The driver of a motor vehicle or street car shall not follow another vehicle or street car more closely than is reasonable and prudent having due regard for the speed of the vehicle and the traffic on and the conditions of the highway. R.S.O. 1990, c. H.8, s. 158 (1).

Headway for commercial motor vehicles

(2) The driver of a commercial motor vehicle when driving on a highway at a speed exceeding 60 kilometres per hour shall not follow within 60 metres of another motor vehicle, but this shall not be construed to prevent a commercial motor vehicle overtaking and passing another motor vehicle. R.S.O. 1990, c. H.8, s. 158 (2).