METAANALYSIS ON TOTAL BRAKING TIME

The total braking time (TBT) distribution is used as an input to two i mportant traffic safety parameters: minimum following gap and stopping sight distance. It is therefore important to accurately estimate the TBT distribution. However, the previously published results on TBT dis tribution vary widely and confuse practitioners. In this paper, a meta -analysis is used in an effort to investigate the sources of variation in the studies of TBT. According to the results of the metaanalysis, significant characteristics of the mean of total braking time are the awareness level of the driver and the country in which the experiment took place. In addition to these two characteristics, both the type of brake stimulus and the distance away from the brake stimulus are foun d to be influential characteristics on the variance of total braking t ime. Based on several combinations of these factors. TBT distributions are reconstructed. It is recommended that the percentile estimates of TBT used for the minimum following gap and stopping sight distance ne ed to be adjusted.