Perception of lack of traffic safety; An exploration of subjective safety This report discusses what has been found in literature about subjective lack of safety, which is the lack of safety as it is experienced during traffic participation, and on the concern about traffic safety that one experiences outside traffic participation. In addition this report discussed the effect of subjective safety on road traffic behaviour, on the acceptance of and compliance with traffic measures, and on prioritization of policy measures. This is followed by a brief survey of the development of views on subjective safety in the Netherlands during the past decades and the effects this has had on the institutionalization of the pursuit of improving road traffic safety. It has also been studied how the experienced lack of safety can be used to detect latent shortcomings of the traffic system. The report ends with a number of conclusions. Generally one feels safe while participating in traffic. Exceptions are those suffering from driving anxiety. In contrast, there is a small group who find traffic participation too safe and actually look for excitement and sensation in traffic. An important aspect of safety perception is behavioural adaptation. This means that under certain conditions, a person starts displaying more unsafe behaviour when one feels safer, and the reverse. However, this is not a one-to-one relation. There are also conditions in which a person does not behave more unsafely when experiencing an increasing feeling of safety. In the course of time, the development of theories about safety perception during traffic participation has experienced a shift in attention from the importance of risk perception (the assessment of the risk and the severity of a crash) to hazard experience (the emotions that are felt when seeing danger). It has often been studied why a person find certain risks very threatening and others not at all, and why there often is difference between a layman's hazard perception and that of an expert. Most studies have shown the relation between subjective safety and objective safety to be weak. This means that there is a difference between what laymen find unsafe and what experts consider to be unsafe. There has also been much study of the sociological processes that enhance subjective lack of safety and maintain it. Strangely, hazard perception in relation to traffic has not been investigated in these mainly international studies. Two factors have been shown to strongly determine the hazard perception of citizens: the degree of 'scariness' and the 'obscurity' of a risk. However, other factors are also important, like voluntary or involuntary exposure to the danger, a natural disaster or a hazard created by people, many victims in incident, a creeping danger, et cetera. The subjective lack of safety can increase when the media pay a lot of attention to a certain risk. A widespread thought is that when a person feels unsafe, his involvement in road safety will be large and, consequently, so will his acceptance and compliance with measures. However, this far from always the case. He often agrees with the principle behind a measure, but this does not mean that he will himself feel obliged to comply with the measure under all circumstances. There is also a difference between passive involvement and active involvement. In the Netherlands, various monitors already measure the subjective lack of safety. This is done because the feelings and opinions of citizens are considered important and to use subjective lack of road safety to detect latent shortcomings of the traffic system. The various methods that are used differ widely and are not always scientifically sound. This report ends with the conclusion that there will always remain a certain tension between objective and subjective safety, because the subjective lack of safety affects traffic behaviour which is also a factor in determining the real, objective lack of road safety. For the well-being of citizens it is important that they feel safe in traffic, but they should not feel so safe that their attention slackens and they start to display unsafe behaviour in traffic.