Driving Restrictions Worsened Air Pollution

The Hoy No Circula, introduced by Mexico in 1989, was intended to reduce air pollution by restricting drivers on the basis of their license plate numbers. For example, car owners with a plate ending in “5” or “6” were prohibited from driving their vehicle on Mondays. In response to the policy, Mexican citizens increased the total number of cars on the road and switched to higher emission vehicles.