Worldwide, more than 1 million people are killed, and several million are injured each year due to transport accidents. Still, since the 1970s, the fatality rate has substantially declined. In many cases, the fatality rate has been cut by more than half (five times less in some instances, such as France and Germany). Road accidents are complex phenomena where several variables often interact (alcohol, network quality, speed, meteorological conditions, driver behavior, etc.). It is possible, however, to group these variables into three major factors: the vehicle, the user, and the environment (infrastructure and traffic). Road safety is an important social stakeholder, and insecurity is a major and often disregarded problem. Therefore, progress occurs in matters of health (emergency) and technology (roads, vehicles). However, the risk itself is not contained because mobility has increased.
Drivers generally tend to underestimate the probability of accidents or overestimate their ability to avoid them. Risk perception becomes a compromise between regulation, psychological tendencies, and the social values of individuals. Other variables must be considered, such as those which diminish awareness and reflexes; aging, fatigue, medicine, drugs, alcohol, etc. Speed is also a factor in road accident risk. The greater the speed, the greater the driving difficulties and the corresponding risk to the driver’s (and other users’) safety. Human factors can be attributed to no less than 85% of accidents. It would thus be impossible to transform the road into a completely safe transport medium.
Given the complexity of the issue with regard to the people, location, and causes implied in accidents, there cannot exist a single all-encompassing approach. Regulation of vehicles, infrastructure, and behavior (education, prevention, awareness, and repression) is commonly perceived as a tool to achieve such a purpose. Road safety acts can influence the consequences of accidents. For example, speed limits, better public transit management, restricted time periods for automobile access in specific neighborhoods, and lanes are methods assumed to have an impact. It is important to remember that the amount of accidents is proportional to mobility, and it is impossible to reduce one without directly impacting the other.