Wrong-way driving on motorways constitutes the cause for a small number of severe accidents, as a result of which there is an annual average of 5 fatalities and 12 wounded persons. Understanding the causes of wrong-way driving is of importance for evaluating existing measures for prevention and for taking possible further measures. The available electronic source files on accidents don't contain information regarding the location where and the way in which the wrong-way driving starts. To obtain this information the original accident registration sets and the more elaborate accident reports were analysed. The accident reports proved to give more insight in the way that wrong-way driving starts. The focus on these reports, however, lies more on the crash itself and determining a culprit than on the preceding causes. About half the wrong-way movements start by entering the off-ramp, the other half starts by turning (mainly on traffic lanes) and movements alike. Entering the off-ramp mostly happens in the darkness by somewhat elderly drivers (55 up). These drivers want to enter the motorway via the on-ramp but make a slip in executing their plan and turn left too early, so that they (since Dutch motorways are designed for driving on the right-hand side) enter the first road instead of the intended second road on their left. Entering the off-ramp happens both on partial cloverleaf ramps and on full diamond ramps and seems to be a problem in processing the visual information from the road environment. Turning happens by somewhat younger drivers who usually make a conscious mistake to undo an earlier error in reaching the desired destination. Because of selective registration and missing data no further insight is gained in the effect of alcohol on wrong-way driving. Most of the wrong-way drivers aren't driving under influence. Drivers who are going the wrong-way tend to keep right, the crash opponent usually just started overtaking. Summons for interviews with wrong-way drivers only gave very limited results. Wrong-way drivers listed confusing situations and inattention as causes for wrong-way driving. In accident reports there is little information about the supposed causes for unplanned wrong-way movements and confusing situations are rarely mentioned. The emphasis for further research and measures lies on accidentally entering the off-ramp by turning left too early. This is the largest homogeneous group of errors and because of its nature (slip) and location this type of error is the easiest to prevent. Case-studies on location showed that the environment of the interchange could evoke turning left too early. A highly visual attractive off-ramp and poor visibility of the on-ramp can lead drivers to the off-ramp. Worn road markings and signs that aren't placed or not placed in the right positions don't make clear which actions are allowed or restricted. Turning to the off-ramp is not prevented by the angle at which the off-ramp can be reached. Much of the situations described don't meet regulations. Not all environmental factors influencing turning left too early are known or can be translated into an experimental task. For those reasons laboratory- or simulator studies aren't (at this moment) the best suited methods for gaining further insight in this type of error. By applying case-control methodology in the reviews of all ramps, proposed by the Ministry of Transport and Public Works, the hypothesis on the properties of wrong-way ramps can be tested and occurring situations that need revision can be dealt with. The wrong-way driver is usually held legally responsible for the accident and its consequences. If an accident is due to the responsibility of a third party Dutch legislation provides a possibility to appeal to circumstances beyond one'scontrol. The road authority is legally responsible for accidents that happen due to not meeting the needs for roads in the given conditions. Dutch jurisprudence proves that the road authority must take the presence of less skilled drivers into account when designing and maintaining roads. The road authority might be held responsible in cases where confusing situations due to not satisfying regulations or minimal maintenance can cause wrong-way driving. The separation between administration of the ramp and crossroad could cause juridical and practical complications. Wrong-way driving can usually not be attributed only to diminished driver skills, environments that are not optimally adapted to its users are a major concern. Expensive measures are not (cost-)effective because of the limited number of victims of wrong-way driving and the many locations of implementation. Other demands for measures are: simplicity, early effect, no disruptance for right-way traffic and no false alarm. If the hypothesis on the characteristics are correct, satisfying the existing regulations for traffic signs and visibility of the on-ramp and timely maintenance of road markings is one of the main measures against wrong-way driving. The "Wrong way" traffic signs in the median between on- and off ramp provide drivers who are correctly driving up the on-ramp with a false alarm. This can decrease the effectiveness of the signs when accidentally entering the off-ramp. Placing or covering the signs in a way that they are not visible as intended to traffic on the on-ramp is recommended. Other recommendations are using wrong-way arrows or other markings on the off-ramp and constructing an extended median on the crossroad to guide drivers to the on-ramp and obstructing entering the off-ramp. (Author/publisher)
Abstract