The objective of this study was examine the driver’s braking behavior while approaching zebra crossings under different safety measures. A configuration of zebra crossing without treatment (baseline condition) and three safety measures (curb extensions, parking restrictions and advance yield markings) were analyzed. The speed reduction time (i.e. the elapsed time between the initial speed value when the driver releases the accelerator pedal or starts to brake in response to a pedestrian crossing and the minimum speed value when the driver yields to the pedestrian) was the variable used to describe the driver’s behaviour. Forty-two drivers drove a driving simulator on an urban scenario in which the baseline condition and the safety measures were implemented. About 500 speed profiles of the drivers when approaching zebra crossings were analyzed and several vehicle dynamic variables were obtained. The speed reduction time was modelled with a parametric duration model to compare the effects on driver’s braking behavior of vehicle dynamic variables and different countermeasures. The parametric accelerated failure time (AFT) duration model with a Weibull distribution identified that the vehicle dynamic variables and only the countermeasure curb extensions affected, in a statistically significant way, the driver’s speed reduction time in response to a pedestrian crossing. The speed reduction time for curb extensions was higher (statistically significant) than those for the baseline condition and the other countermeasures. No other difference was statistically significant. This result shows that the driver, due to the improved visibility of the pedestrian allowed by the curb extensions, was able to receive a clear information and better to adapt his approaching speed to yield to the pedestrian, avoiding abrupt maneuvers. This also means a reduction of likelihood of rear-end collision due to less aggressive braking. The effectiveness of the countermeasure curb extensions was also confirmed by the data on self-reported driving behaviours, which were collected during the driving simulator experiment.
Bella, F., Silvestri, M. (2015). A HAZARD-BASED DURATION MODEL OF THE SPEED REDUCTION TIMES OF DRIVERS AT PEDESTRIAN CROSSINGS. In Proceedings of 2015 Road Safety & Simulation International Conference.