Motor vehicles overtaking cyclists on two-lane rural roads: Analysis on speed and lateral clearance

  • Published: Safety Science 92, 2017: p 302-310
  • Authors: Llorca, C., Sngel-Domenech, A., Agustin-Gomez, F. & Garcia, A.
  • Date Added: 08 Mar 2018
  • Last Update: 08 Mar 2018
  • Format: html


The aim of the paper was the analysis of compliance and adequacy of the 1.5 m lateral distance criterion with respect of objective and subjective risk measures.

The study had the following objectives:

  • Compare the effect of lateral clearance and overtaking vehicle speed (and their combination, in terms of aerodynamic forces) with a rider’s subjective and relative risk perception on the different road segments.
  • Analysis of the compliance and adequacy of lateral clearance based criteria.
  • Analysis of the effect of bicycle type, road alignment and presence of opposing traffic.

The initial hypothesis of the research was that both lateral clearance and overtaking vehicle speed affect the subjective perception of each road segment. The higher the lateral clearance and the lower the speed, the safer the rider perception.


The observation of overtaking manoeuvres was carried out using an instrumented bicycle. A professional cyclist rode the bicycle at speeds between 15 and 25 km/h, on seven rural road segments, resulting in the characterisation of each motor vehicle overtaking manoeuvre. 2928 overtaking manoeuvres were characterised.

Key Findings:

  • The analysis suggested that lateral clearance is not the only factor that influenced rider’s risk perception, although current standards are only related to it.

  • A combined factor of lateral clearance, vehicle type and vehicle speed had a more significant correlation with the perceived risk.

  • Results showed that the effect of heavy vehicles on bicyclists was also strong.

  • The combined factor of clearance and speed was higher on tangent sections where overtaking was permitted.


Bicycle; Overtaking; Sport cycling; Two-lane rural road; Lateral clearance; Instrumented bicycle; Risk perception


Focused on cycling on rural roads