In many European countries, it is a political goal that future growth in local travel should be absorbed by sustainable transport modes. Concerns that increased walking and cycling produce more accidents have been countered by the “safety in numbers” (SiN) argument. According to SiN, the more walkers/cyclists there are in a population, the lower their risk. SiN has mainly been demonstrated in cross-sectional studies, but the mechanisms behind the effect have yet to be proven. Previous studies have mostly relied on register data. The current study carried out in 2013 and 2014 tests the existence of this effect in a more controlled manner. This is achieved by two data sets: (1) a panel study with interviews of cyclists, pedestrians and car drivers, where participants are recruited from a time series study in Oslo (preliminary results presented at ICSC in 2013) and (2) similar roadside survey data from Oslo and Aalborg. By exploiting the natural seasonal variation in cycling frequency, and by using a repeated measures design we can further control for other factors suggested to lie behind the SiN mechanism. Results from the study indicate that bicyclists experience decreased levels of inattention from car drivers with increased numbers, and that car drivers report to be more attentive with increased numbers of bicyclists. (Author/publisher)
Abstract