The project „Auswirkungen von Autobahnausbauten auf die Verkehrssicherheit‚ (short A3V) deals with the consequences on road safety of expanding motorways from 2 to 3 and 3 to 4 lanes in both directions. The road safety is measured by the number of injury accidents as well as the severity of injuries of the road users. Therefore the accidents between 2007 and 2009 are analysed. Special attention has been paid to different road characteristics (e.g. alignment, shoulder lane). Sections on Austrian motorways as well as sections on Austrian expressways are chosen for this project and are analysed with the help of the „Observational Before-After Study". *Evaluation after ‚average daily traffic volume‘ (JDTV) The accident figures indicate a clear trend of growing daily traffic volume; however, the single accident rate decreases with increasing daily traffic volume. The rear end collision rate rises with growing daily traffic volume. *Road sections with 1 and 4 lanes Due to a small sample size, there are no restrictions through indicators possible in road sections with one and four lanes. *Road sections with 2 lanes The accident figures of road sections with two lanes are almost the same in all evaluations (i.e. with increasing restriction through indicators). *Road sections with 3 lanes The accident cost rate (as well as the severity of injuries) on ‘straight and plain’ routes with three lanes and compulsory 130 km/h is about 2.3 times higher than with compulsory 100 km/h maximum speed. *Differences between 1 and 2 lanes In total, on a highway with one lane the accident rates as well as the casualty rates are considerably higher (+32% and +80%) and the fatalities cost rates as well as accident cost rates are substantially higher (+300% and +148%) than on analysed road sections with two lanes. *Differences between 2 and 3 lanes The accident figures of highways with two and three lanes only differ slightly. *Differences between 3 and 4 lanes The probability of having an injury accident or to be killed in an injury accident rises on a highway with four lanes (UR +56% and VR +40%). However, the injury severity in the case of an injury accident is lower on a highway with four lanes (UKR -25%). (Author/publisher)
Samenvatting