Which intersection types are safest?

Answer

Research [9] shows that roundabouts are the safest intersections. The list of intersection types below is in order of safety, from safest to least safe[i]:

  1. Roundabout. According to research comparing the crash risks of different types intersections [9], roundabouts are safer than conventional intersections. A recent publication [10], however, came to the contrary conclusion that more traffic injuries occur at roundabouts than conventional intersections. It is not clear to what degree this recent result is influenced by the fact that relatively unsafe intersections are more likely to be converted into a roundabout than relatively safe intersections. Before-and-after studies conducted at the same locations [11] [12], have shown that the conversion of an intersection into a roundabout lead to a substantial reduction in traffic casualties.
  2. Prioritised intersection. Traffic volumes at these intersections are often lower than at signalised intersections. The design of a priority intersection is simpler than that of a signalised intersection. This results in less complex situations and, thus, fewer crashes.
  3. Signalised intersection. These intersections are generally less safe than other types of intersection. The choice for a signalised intersection is often made when other intersection types would not be able to handle the high number of passing motor vehicles. Signalised intersections are often complex because of their higher capacity, which may reduce their safety. The capacity of an intersection is determined by the number of lanes of the legs and by traffic distribution across these legs.

Furthermore, a new intersection has recently been introduced: the bow-legged intersection (for a description, see the section What are the different types of intersection? ). It is, however, still too early to include the bow-legged intersection in the list above, since bow-legged intersections have not yet sufficiently been evaluated. There are, however, some graduate studies of bow-legged intersections. They generally conclude that a bow-legged intersection has more points of conflict than a single-lane roundabout. The points of conflict are, however, further apart than at priority intersections, the types of conflict are different than at other intersection types and conflicts occur at lower speeds.

For more information about the safety of bow-legged intersections, see the following three graduate studies: [13] [14] [15].


[i] Unprioritised intersections, and therefore right of way for traffic coming from the right, are not included in the list because they belong to a different scope, viz. residential areas (30 and 60 km/h zones). They can therefore not be compared to the intersections in this list.

Part of factsheet

Roundabouts and other intersections

About one third of the road deaths on Dutch roads occur at intersections. Within the urban area, this amounts to half and outside the urban area to Meer