Improving cycling safety through infrastructure design: A bicycle simulator study

This study investigated the impact of two road treatments on cyclist behaviour using an bicycle simulator. The treatments were sharrows (presence or absence) at a roundabout and widening an on-road bike lane (width 1.2 m or 1.8 m) on a curved mid-block section of the road. Outcomes collected included count (e.g. number of lane excursions) and continuous responses (lane position upon entry into the roundabout, in metres from the curb). A convenience sample of 21 Perth-based participants was recruited between 1 July and 30 September 2021. The results found that the presence of sharrows was not significantly associated with the distance from the left curb when entering a single lane roundabout. However, females rode 0.44 m further from the left curb when entering the roundabout than males, which was significant (95 % CI = 0.02–0.85; p = 0.04). Riders, aged 26–40 years, also rode 0.61 m further from the left curb when entering the roundabout than riders aged 18–25 years, which was also significant (95 % CI = 0.18–1.05; p = 0.01). The rate of bike lane excursions significantly decreased by 68 % for the wide bike lane on the curved mid-block section of the road compared to the standard width bike lane (IRR = 0.32; 95 % CI = 0.11–0.88; p = 0.03). Riders, aged 26–40 years, had a significant increased rate of 8.72 excursions than riders aged 18–25 years (IRR = 8.72; 95 % CI = 3.32–22.89; p < 0.001). This study highlights that increasing the bike lane width on curved sections of mid-block roads may benefit cyclists. However, the value of sharrows in a single lane roundabout is less clear.