Human vision is not well adapted to night-time conditions. Hence, road users need technical solutions, such as street lighting and retroreflective materials, in order to be able to drive, cycle or walk safe at night. Night-time traffic implies some certain problems, for example glare and difficulties with detecting obstacles and estimating distances. Different groups of road users have different prerequisites and needs, and the problems encountered may thus vary. In order to improve traffic safety and accessibility under night-time conditions, the needs and problems of all road user groups must be taken into consideration. It is also important to adapt the technology that aims to facilitate night-time traffic to the road users who will use it. The aim of this literature study is to review recent research on night-time traffic from a road user perspective. The report discusses road users’ behaviour, needs and problems in relation to other road users as well as to traffic environment. The study includes 128 references from 1998–2008 and it mainly concerns urban areas. Accident statistics show that pedestrians are at a greater risk of having an accident at night than during daylight conditions. For drivers, research indicates that there are no substantial differences in accident risk between darkness and daylight, when the influence from other factors such as alcohol and drowsiness is controlled for. A problem that is frequently discussed in literature is drivers’ difficulties in detecting pedestrians. One explanation given is that the ability to steer a vehicle is not affected by darkness, which results in the driver not being aware of the reduced visibility and thus not adjust the driving to the present conditions. In addition, pedestrians tend to overestimate their own conspicuity, which may cause them to expose themselves to potential risky situations. Many older drivers avoid night-time driving. Increased sensitivity to glare and age-related visual impairment may be some of the reasons, but literature does not provide a complete picture. Bicyclists’ needs and problems in night-time traffic are not well documented. Accident statistics indicate that bicyclists may be at an increased risk of having an accident in darkness, but besides that almost no information is available from literature. Also, there is very little literature on visually impaired people and their experiences of night-time traffic. Some eye diseases are very common, especially among older people, and research shows that many of those affected continue to drive. Knowledge about these road user groups is thus important. Regarding the interaction between road users and road environment, mainly studies about street lighting were found. Among other things, the studies report about new lamp types that both improve visibility and have lower energy consumption. Other studies indicate that the visibility of road markings seldom meets the road users’ demands. Literature on traffic lights and traffic signs was limited to a few studies, while no information at all about road surfaces was found. An area interesting for further research is visibility and detection of pedestrians, which includes behavioural aspects as well as technical solutions. Other areas that are interesting for further studies are older and visually impaired road users’ experiences and problems in night-time traffic, and also bicyclists’ visibility and needs. (Author/publisher)
Samenvatting