Traffic conflict has been adopted as a road safety surrogate measure, especially for specific road entities and road user groups. It is believed that factors affecting the occurrence and severity of traffic conflicts would also affect those of road crashes. In this study, the effects of driver age, traffic condition and driving time on the severity of rear-end conflicts on inner-city roads were examined using driving simulator approach. A total of 41 drivers completed the driving simulator experiment. Their responses to 82 challenging events were assessed. Performance indicators including braking reaction time (BRT), minimum time-to-collision (TTC min ), time exposed time-to-collision (TET), time integrated time-to-collision (TIT) and the conflicting speed were considered. A TTC min of 3 seconds or less was adopted as a threshold to screen out 68 rear-end conflicts for subsequent analysis. Results indicated that low traffic flow …