Background: Drivers play a crucial role in accidents. By paying attention to brake lights, a driver may find out about danger and react adequately. Rear-end collision accidents are caused by the driver’s inattention or slow reaction. This study aimed to determine the effect of dynamic flashing brake lights (7 Hz) on drivers’ brake reaction time using the driving simulator. 
Materials and Methods: This experimental study was done on 46 volunteer drivers (10 females and 36 males). After verification of drivers’ vision health by an optometrist (10/10 complete and non-color blindness) and responding to a demographic questionnaire, the participants were subjected to drive for an hour during day and night using a driving simulator system with the standard and dynamic flashing brake lights. 
Results: The results indicated that for each 1 year increase in the drivers’ age, the brake reaction time decreased 11.585 ms. Women had slower brake reaction time than men (75.52 ms). No significant relationship was found between the driving condition and brake reaction time. Computer driving gamers had shorter mean reaction time compared with non-game players. The time elapsed since taking a driving license had no significant effect on reaction time. Using flashing brake lights reduced the brake reaction time of drivers (323.42 ms; P<0.001).
Conclusion: The current research using dynamic flashing brake lights with a flashing frequency of 7 Hz showed that flashing brake lights significantly reduced the brake reaction time. This reduction was equivalent to 10.78 m at a speed of about 120 km/h or 7.19 m at 80 km/h.