295 EKSPLOATACJA I NIEZAWODNOSC – MAINTENANCE AND RELIABILITY VOL.14, NO. 4, 2012 Article citation info: (*) Tekst artykułu w polskiej wersji językowej dostępny w elektronicznym wydaniu kwartalnika na stronie www.ein.org.pl JURECKI R, JAśKIEWICZ M, GUZEK M, LOZIA Z, ZDANOWICZ P. Driver’s reaction time under emergency braking a car – Research in a driving simulatory. Eksploatacja i Niezawodnosc – Maintenance and Reliability 2012; 14 (4): 295–301. Rafał S. JURECKI Marek JAśKIEWICZ Marek GUZEK Zbigniew LOZIA Piotr ZDANOWICZ DRIVER’S REACTION TIME UNDER EMERGENCY BRAKING A CAR – RESEARCH IN A DRIVING SIMULATOR CZAS REAKCJI KIEROWCY W WARUNKACH AWARYJNEGO HAMOWANIA SAMOCHODU – BADANIA W SYMULATORZE JAZDY SAMOCHODEM* Extract. The paper presents results of research on the reaction time of drivers of motor vehicles in case of accident risk. These stud- ies have been conducted in an autoPW driving simulator - research project N509 016 31/1251. During a simulated pre-accident situation, a test driver, as he was trying to avoid a collision with an obstacle, has been forced to perform a braking manoeuvre. 107 people of different age and driving experience have been studied. Various scenarios describing risk situations (the speed of a car driven by a tested driver, the distance between the vehicles at the initial moment) have been considered.Reaction times were determined at the controls of the vehicle and they have been presented in a time to collision function. The presented results provide important information on the analysed subject (for instance reaction time dependence on risk time). They have also confrmed the usefulness of this type of simulation studies in connection with the possibility of fairly accurate reproduction of the environment appearance and an event scenario in relation to possible real situations. Key words: tests of drivers, drivers' reaction time, risk time, car driving simulators. W publikacji przedstawiono wyniki badań dotyczące czasu reakcji kierowców pojazdów samochodowych w sytuacjach zagrożenia wypadkowego. Badania te zostały wykonane w symulatorze jazdy samochodem autoPW w ramach projektu badawczego N509 016 31/1251. W zainscenizowanej sytuacji przedwypadkowej, badany kierowca próbując uniknąć zderzenia z przeszkodą, zmuszony był do wykonania manewru hamowania. Przebadano 107 osób różniących się wiekiem i doświadczeniem w prowadzeniu samo- chodu. Rozważono różne scenariusze opisujące sytuacje zagrożenia (prędkość samochodu, którym kierował badany, odległość pomiędzy pojazdami w chwili początkowej). Wyznaczono czasy reakcji na elementach sterowania pojazdem i przedstawiono je w funkcji czasu ryzyka (ang. time to collision). Zaprezentowane wyniki dostarczyły istotnych informacji na analizowany temat (np. zależność czasu reakcji od czasu ryzyka). Potwierdziły też przydatność prowadzenia tego rodzaju badań w symulatorach w związ- ku z możliwością dosyć wiernego odwzorowania wyglądu otoczenia i scenariusza zdarzeń w stosunku do możliwych rzeczywistych sytuacji. Słowa kluczowe: badania kierowców, czas reakcji kierowców, czas ryzyka, symulatory jazdy samochodem. 1. Introduction According to statistical data, for instance [16, 19, 20], the most common cause of road accidents are persons driving the vehicles. It has been estimated that approximately 70% of accidents in Poland is a result of incorrect operation of a driver. Reaction time has been among the many features that characterize its function in the event of accident risk on a road. In short, it can be defined as the period from the time a threat appears to the moment a driver takes certain actions on vehicle controls to avoid an accident. This parameter has a direct impact on the course of an accident situation, and road safety at the same time. On the other hand, it is one of the basic data adopted in the calculations carried out by ex- perts from automotive and traffic engineering (and court experts) in the process of reconstructing accidents. The results of this analysis depend on values adopted in these calculations, which in turn, influ- ence court's decisions concerning guilt of participants of the event or its absence. From both points of view, research on reaction time are thus fully justified. The paper presents selected results of extensive research, conducted throughout 2007-2010, whose primary purpose was to gather particular reaction times. These studies have been conducted by three teams: the Kielce University of Technology (leader), the Technical University of Warsaw and Cracow University of Technology, under project no. N509 016 31/1251 "Development and update of the reaction times database of vehicle drivers." 2. Justification of the need to test reaction time Data on drivers’ reaction times are crucial in the manuals and training materials for court experts and automobile en- gineering and traffic experts. Values presented in many pub- lications differ significantly. However, as mentioned earlier, values adopted in the analysis by a court expert may strongly influence final decisions on drivers’s fault.