Driver behaviour in intersections: Formal and informal traffic rules

Abstract

Drivers’ behaviour in intersections is not only influenced by the rules of priority in the intersection but also by the design of the intersection as well as the behaviour of other road users. If behaviours that supplement or contradict formal traffic rules become common in a particular traffic intersection, it is an indication that an informal traffic rule has been used. In the present study a sample of 1276 Swedish drivers (aged 18–74 years) responded to questions about how often they would yield to another driver in 10 hypothetical crossing situations. In all crossing situations the respondents were told that there was no major road, implying that they should always yield the right of way to traffic coming from the right (the right-hand rule ). The results showed that drivers’ reported behaviour varied over different intersections. As expected, the formal rule of priority (i.e., the direction from which the other driver was coming) was an important determinant for drivers’ yielding behaviour. However, cues for informal rules such as the other driver’s behaviour and road breadth were also of importance. Different groups of drivers could be identified according to their strategies of yielding behaviour. One group of drivers reported that they rarely yielded, whereas another group reported that they always did so. A third group complied with the right-hand rule most of the time, whereas the behaviour of a fourth group varied over intersections. The implications of the results and the appropriateness of the right-hand rule are discussed.