The TAC SafeCar study evaluated the impact of three Intelligent Transport System technologies, alone and in combination, on driver performance:​ Intelligent Speed Adaptation, Following Distance Warning and a Seatbelt Reminder system for all seated occupants. The project had several aims:​ to evaluate the technical operation of these technologies;​ to assess the acceptability to drivers of them;​ and to evaluate, in an on-road setting, the impact of them, alone and in combination, on driver performance and safety. Twenty-three fleet car drivers (15 treatment and 8 control drivers) participated in the on-road study. Each participant drove a SafeCar for at least 16,500 kilometres. The SafeCar project was the first to evaluate the effects on driving performance of long-term exposure to a Seatbelt Reminder system. The results, reported in this paper, revealed that driver and passenger interaction with the Seatbelt Reminder system led to large and significant decreases in the percentage of trips where occupants were unbelted, in the percentage of total driving time spent unbelted, and in the time taken to fasten a seatbelt in response to the seatbelt warnings. The Seatbelt Reminder system was rated by drivers as being useful, effective and socially acceptable, and use of it led to a decrease in drivers’ subjectively reported mental workload. Based on the results of the study, use of the Seatbelt Reminder system is estimated to save the Australian community approximately AUD $335 million per annum in reduced HARM costs. These findings were yielded even though initial seatbelt wearing compliance rates in the community were high, suggesting that Seatbelt Reminder systems can be effective in improving seatbelt compliance among occupants who already have high wearing rates