Disaggregate Exposure Measures and Injury Frequency Models of Cyclist Safety at Signalized Intersections

Abstract

This paper proposes a new approach to represent cyclist risk exposure. This approach considers disaggregate motor vehicle and cyclist flows and develops cyclist injury frequency models. Three definitions of risk exposure were used in this research, including aggregated flows, motor vehicle flows aggregated by movement type, and potential conflicts between motor vehicles and cyclists. As an application environment, a large sample of signalized intersections on the island of Montreal, Quebec, Canada, was used, along with data that comprised disaggregate motor vehicle and cyclist flows. Several negative binomial models were fitted to the data. This study showed that cyclist collisions were sensitive to changes in both cyclist and motor vehicle flows. A 10% increase in bicycle flow was associated with a 4.4% increase in the frequency of cyclist injuries. A 10% increase in the total number of motor vehicles that passed through the intersection would result in a 3.4% increase in cyclist injury occurrence. When motor vehicle flows were considered on the basis of movement type, right-turn movements had a great effect on injury occurrence. Similar results, which identified right turns as having the greatest effect on cyclist injuries, were produced when the impact of potential conflicts was determined. The number of bus stops in the proximity of the intersection increased cyclist injury occurrence. Some geometric design factors, such as the presence of a median, parking entrance, and the number of intersection legs, were tested. The effect, however, was found to be statistically nonsignificant.

Comparing the effects of infrastructure on bicycling injury at intersections and non-intersections using a case–crossover design

“…Two other recent studies examined the impact of increased cyclist volume at intersections: one in Finland showed lower crash risk with increased cyclist volume at a newly installed raised bicycle crossing; 28 and one in Montréal found injury risk increased at a lower rate than cyclist volumes at signalised intersections. 29 Our results may thus not be generalisable.…”

Built environment factors in explaining the automobile-involved bicycle crash frequencies: A spatial statistic approach

“…In terms of street elements, bus stop density is positively associated with bicycle crash occurrences (Miranda-Moreno et al, 2011b;Strauss et al, 2013;Wei and Lovegrove, 2012). Among current studies, street lighting has only been included for modeling bicycle injury severity (Kim et al, 2007;Klop and Khattak, 1999), but barely been considered for bicycle crash frequency.…”

“…Among current studies, street lighting has only been included for modeling bicycle injury severity (Kim et al, 2007;Klop and Khattak, 1999), but barely been considered for bicycle crash frequency. Moreover, parking entrance shows an insignificant relationship with bicycle crash frequency (Miranda-Moreno et al, 2011b), but parked vehicles close to separated bike facilities are associated with an increased risk (Vandenbulcke et al, 2014).…”

“…Among the travel demand variables, vehicle volume (Hamann and Peek-Asa, 2013;Schepers et al, 2011), bicycle volume (Hamann and Peek-Asa, 2013;Miranda-Moreno et al, 2011b;Schepers et al, 2011;Strauss et al, 2013) and large vehicle volume (Vandenbulcke et al, 2014) have been included for modeling, and all of them suggest positive associations with bicycle crash frequency. As for traffic control variables, a higher density of low-speed streets (<15 mph) is negatively associated with the number of bicycle crashes (Siddiqui et al, 2012), while more roads with high-speed limits (>35 mph) have an increased number of bicycle crashes (Chen and Fuller, 2014;Siddiqui et al, 2012).…”

A Population Approach to Transportation Planning: Reducing Exposure to Motor-Vehicles

“…In transportation research, the volume and speed of motor vehicle traffic could be considered two of the fundamental causes of collisions, for all road users [16, 17]. Throughout the paper, we consider exposure to moving vehicles as a fundamental cause of road traffic deaths and injuries.…”