Speeding tickets have a strong, immediate and very lasting effect. As a study by the Hertie School in Berlin and Charles University in Prague shows, speeders who are fined subsequently observe the speed limit in four out of five trips.

Even two years after this event, a driver who has been fined once still drives below the speed limit at a significantly lower speed and with a higher probability than before. This effect can be observed not only at the place where a driver was flashed, but also at other places.

For the study, Christian Traxler (Hertie School, Berlin) and Libor Dusek (Charles University, Prague) evaluated anonymized data from a "Section Control" radar system near Prague: a total of 26 million trips by 1.3 million different vehicles. Section Control" is a stationary digital camera system that records the data of every passing car on a specific route, not just spotting speeders. The wealth and linkability of this data made such a detailed study of the effect of sanctions for speeding violations possible for the first time.

Christian Traxler: "The data document a clear learning effect that radar systems have after receiving a speeding ticket. Drivers learn that these devices detect speed and automatically follow up on fines in the event of violations, and change their behavior accordingly. Interestingly, the amount of the fine does not matter for the change in behaviour. From now on, drivers who had to pay 35 euros complied with the speed limit just as often as those who received a fine of 70 euros.

The complete study can be found here: www.cesifo.org