Perceived time savings by travelling faster is often cited as a motivation for drivers’ speeding behaviour. These time savings, however, come at a cost of significant road injuries and fatalities. While it is known that drivers tend to overestimate the time savings attributable to speeding there is little empirical evidence on how much time drivers genuinely save during day-to-day urban driving and how this relates to speeding-related crashes. The current paper reports on a study to address the lack of empirical evidence on this issue using naturalistic driving data collected from 106 drivers over a period of five weeks. The results show that the average driver saves 26 seconds per day or two minutes per week by speeding. More importantly, the cost of these time savings is one fatality for every 18,947 hours saved by the population on 100 km/h roads and one injury for every 1,407 hours saved on the same roads. Full speed compliance – and consequently a dramatic reduction in the road toll – could be achieved through almost imperceptible increases in travel time by each driver
