Collection problems and the promise of self-cancelling tickets. Paper presented at the 53rd Annual Meeting of the Highway Research Board HRB, Washington, D.C., January 1974.

Collection motor vehicle user charges by time-calibrated self cancelling tickets (timer-tickets) are discussed. The timer ticket, when bent or scratched, changes colour to red. This shows that the ticket has been activated. It also started a chemical reaction that, after a preset time, results in a second colour change, to a blue. Categories in which timer-tickets may be used are discussed.