The idea of the front brake light has been around for some time, but no vehicle manufacturer has as yet implemented it. A research team led by Ernst Tomasch from the Institute of Vehicle Safety at Graz University of Technology (TU Graz) in collaboration with the Bonn Institute for Legal and Traffic Psychology (BIRVp) has now analysed their effect on road safety in an accident reconstruction study. The analysis of 200 real accidents at road junctions showed that – depending on the reaction time of road users – 7.5 to 17 per cent of collisions would have been prevented by an additional brake light on the front of the vehicle. In up to a quarter of cases, the lights also would have reduced the speed of the impact and thus mitigated injuries. The results of the study were recently published in the scientific journal Vehicles.
Front brake lights signal to oncoming road users and, to a certain extent to road users approaching from the side, that a vehicle is braking and, if the front brake lights go out, that a stationary vehicle could start moving. “This visual signal can significantly reduce the reaction time of other road users,” says Ernst Tomasch. “This reduces the distance needed to stop and ultimately the likelihood of an accident.”
As vehicles with front brake lights have so far only been used in real road traffic as part of a field test in Slovakia, the researchers had to resort to a combination of accident reconstruction and simulation. They used 200 car accidents at Austrian road junctions recorded in the Central Database for In-Depth Accident Study (CEDATU). Firstly, the sequence of events of all accidents was reconstructed in detail. The researchers then simulated the events again, assuming that the vehicles coming from subordinate roads were equipped with a front brake light. If the front brake light was visible to road users on the priority road, a faster reaction was assumed in the simulation, as a result of which the distance needed to stop was reduced. From the differences between real accidents and simulations, the researchers drew conclusions about the accident-prevention effect.
Front brake lights light up green instead of red and can be easily integrated into the design of vehicles. Existing vehicles could also be retrofitted relatively cheaply. “However, front brake lights only have a positive effect if other road users can actually see them. This was not the case in around a third of the reconstructed accidents due to the unfavourable angle between the vehicles involved,” says Ernst Tomasch. “We therefore recommend fitting the brake lights to the sides of the vehicles as well and investigating the potential additional effect.”
Vehicles
Computational simulation/modeling
Not applicable
Assessment of the Potential of a Front Brake Light to Prevent Crashes and Mitigate the Consequences of Crashes at Junctions
29-Apr-2025