Driver behaviour towards circulating cyclists at roundabouts

Belinda la Cour Lund, Paper from TRB Annual Meeting 2009

It is a well known fact that roundabouts are safer for motor drivers than for cyclists. The main part of accidents occurs between motor vehicles entering or leaving the roundabout and circulating cyclists. In order to obtain more knowledge about why some entering motor drivers overlook circulating cyclists; the Danish Road Directorate has conducted a study of driver behaviour at roundabouts in urban areas.

Is it possible to change the interaction between vehicle drivers and cyclists in relation to roundabouts by changing the design, in a way that makes it safer for cyclists? Should roundabouts be designed with or without cycle facilities? And does visibility splays have any importance for drivers overlooking circulating cyclists?

By use of a vehicle simulator together with eye tracking, a study of motor drivers' behaviour towards circulating cyclists in roundabouts in urban areas with or without cycle facilities and varying visibility splays have been conducted. A total of seven different roundabout designs with varying type of cycle facilities in the approach and in the circulation area have been tested.

The seven designs have all been tested with three different visibility splays: Good, Medium and Acceptable.

The results from the analysis, indicates that visibility splays, design and the presence of cycle facilities all have influence on drivers interaction with circulating cyclists when approaching a roundabout. The results indicate that drivers are more attentive to circulating cyclists, when there is no cycle facility.

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