Electronic Stability Control (ESC) is an active safety device for motorvehicles. ESC enhances controllability, and can prevent skidding in cases ofoversteering or understeering. Accidents involving skidding can be prevented, or accident severity can be reduced due to reduced probability of side collisions and roll-overs. Additionally, ESC can influence driver behaviour by informing about low-friction driving conditions. Based on a literature analysis, accident statistics and a review of in-depth accident analyses it is estimated which proportions of different types of accidents mightbe influenced or prevented with ESC. The total amount of "potentially influenceable" accidents can be seen as the theoretical maximum for accident reducing effects of ESC. A relatively large amount of single accidents have potential to be influenced by ESC, and a smaller amount of accidents involving several vehicles. However, not all accidents that may be influencedby ESC can be prevented, but may have less serious consequences. Limitingand enhancing factors for the effectiveness of ESC include type of vehicle, road design, weather, driver behavior, tyres, load, brakes and chassis frame. A metaanalysis is conducted which includes studies that have investigated number and type of accidents involving cars with and without ESC. All studies have found reductions in single accidents for cars with ESC. Onthe average, effect sizes correspond to the estimated maximum for single accidents, but differ depending on how accurate the studies controlled forother simultaneous improvements of active or passive safety. As the estimated maximum is an upper limit for influenceable accidents, not for the total amount of preventable accidents, this effect ist likely to be overestimated. For multi-vehicle accidents, no effects of ESC are found in the metaanalysis, even though accident analyses have shown a potential. In summary, the results show a considerable potential of ESC to prevent accidents and reduce accident severity. Differences between estimates from different methods (analysis of accident reports and statistics vs. metaanalysis) andfor different accident types suggest the presence of interaction effects between ESC and other factors, namely driver behaviour and other active and passive safety systems. Based on the combined results, it will be discussed in what way ESC affects the road-vehicle-driver system. Further improvements of vehicle safety could be achieved by combining ESC with other in-vehicle safety systems (braking assistent, steering assistent, integrativecruise control). Improvements in vehicle safety could be supplemented by road safety measures aiming at improving adaptation of driver behaviour todriving condition by visual (e.g. road markings, chevrons, road studs) orvibratory (rumble strips) guidance. Finally, ESC is likely to affect driver behaviour, and system-design should be such as to prevent risk-taking behaviour and to improve adaptation to driving conditions. For the coveringabstract see ITRD E135582.
Samenvatting