Badania hamowania pojazdov w warunkach miejskich

Abstract

The paper presents some car braking problems in urban conditions. In urban traffic often happen situations, when street crossings are being passed across by cars at the moment, when traffic lights are being changed. Requirements of the rules of the road allow continuing passing the crossroad, if it is impossible without emergent braking to bring the car to a stop after the yellow traffic light lights up or the pointsman rears his hand. Therefore during examination of road accidents experts often must investigate road situations and calculate the braking distance for a case of not emergent braking. There is some lack of publications describing values of deceleration which must be used in calculations for such braking. Thus with the goal of evaluation of numerical values for such braking there were carried out experiments of car braking under urban conditions. The first stage of the experiments was braking at real urban road situations with intensive traffic in streets (car stopping at traffic lights). Braking was executed with the car approaching to a crossroad with the green blinking traffic light for different distances to the crossroad, thus braking intensity was different. Measurements were performed with the device "GPS autocam 1G", its indications were compared with results, measured and saved in the memory of the device "XL Meter". Braking efficiency was subjectively estimated by a skilled driver. The second stage of the experiments was inquiry of car passengers (most of them had driver's license) concerning the braking intensity. The results of this work allow making of proposal to consider as not emergent deceleration the one less than 4.0 m/s~ and to use the value in practice for examination of road accidents.