Measuring the Safety Effect of Raised Bicycle Crossings Using a New Research Methodology

Abstract

Before-and-after study methodology was developed and applied to evaluating the effect on bicyclists’ safety of raising urban bicycle crossings by 4 to 12 cm. In total, 44 junctions were reconstructed in this way in Gothenburg, Sweden. Four of these were studied in detail. Before the implementations, bicyclists were riding either in the roadway or on separate paths parallel to the roadway. The paths then ended with short ramps or curb cuts at each cross street, and bicyclists used nonelevated, marked bicycle crossings, similar to pedestrian crosswalks but delineated by white painted rectangles rather than zebra stripes. The results show that the paths with raised crossings attracted more than 50 percent more bicyclists and that the safety per bicyclist was improved by approximately 20 percent due to the increase in bicycle flow, and with an additional 10 to 50 percent due to the improved layout. However, the increased bicyclist volume means that the total number of bicycle accidents is expected to increase. Besides accident analysis, the change in risk was estimated using four different methods: surveys of bicyclists and experts, respectively; conflict data; and a quantitative expert model. Using a Bayesian approach for combining the results shows that the most likely effect of raising the bicycle crossing is a risk reduction of around 30 percent, compared with the before situation with a conventional bicycle crossing. Motorists and pedestrians also saw safety benefits from this traffic-calming measure.

Car driver attitudes, perceptions of social norms and aggressive driving behaviour towards cyclists

“…Scheepers et al, 2014;Wegman et al, 2012). In fact, good cycling infrastructure increases bicycle usage (Gårder et al, 1998). However, it is not always available.…”

Models of perceived cycling risk and route acceptability

“…There have been junction based studies and these have found that reductions in risk for bicycle traffic may be obtained by specific features such as raised crossings (Gårder et al, 1998), careful design of the whole junction (Gårder et al, 1994) or by virtue of larger flows of bicycle traffic (Ekman, 1996;Wang and Nihan, 2004). Landis et al (2003) found that the perception of level of service for a straight on movement through a junction was related to running lane width, junction crossing width and volume of traffic.…”

Utilizing Egocentric Video and Sensors to Conduct Naturalistic Bicycling Studies

“…The findings suggest that bike lane presence, crossing traffic volume, speed limit, speed parking, traffic signals, and crossing distance affect levels of service and comfort at intersections (Carter, Hunter, Zegeer , & Stewart, 2007) (Landis, Vattikuti, Ottenberg, Petritsh, Guttenplan, & Crider). In terms of the route, bicycle paths separated from traffic have been found to be preferred by users (Garder, Leden, & Pulkkinen, 1998) (Sener, Eluru, & Bhat, 2009) (Winters, Davidson, Kao, & Teschke, 2011). Models utilizing data from a smartphone app (ORcycle) that focuses on measuring comfort levels also show that traffic and commercial vehicles are the most important factors that decrease cyclists' comfort levels.…”

“…When the bicycle path is raised, the vehicles are likely to reduce their speed, thus reducing the risk of a crash. (Garder, Leden, & Pulkkinen, 1998). Dill et al (2007) identified that the perception about availability of comfortable bicycle facilities is a strong factor affecting bicycle ridership and bicycle mode share (Dill & Voros, 2007).…”

“…Landis et al asked cyclists to rank various signalized intersections in terms of safety and comfort, finding that the main variables affecting level of service are traffic volume, total width of outside through lane and bike lane, and total crossing distance (Landis, et al, 2003). Garder et al (1998) surveyed different experts on cyclists' safety across the world, and studied the speed and behavior of cyclists in a bike path before and after the implementation of different types of bicycle crossings. The findings suggest that cyclists have a higher risk of injury at intersections that are part of bike lanes than shared roadways; intersections on shared roadways likely force the cyclist to take the lane, making him/herself more visible to the driver who is turning.…”