Traffic conflicts involving speed-pedelecs (fast electric bicycles): A naturalistic riding study

Speed-pedelecs -fast electric bicycles offering pedal support up to a speed of 45 km/h- are a recent, environmentally friendly, and mobility efficient innovation. However, their high travel speed may increase crash and injury risk. Due to their recent introduction accurate crash data are not available yet. Since near-crashes may serve as a proxy for crashes this study analyzed traffic conflicts (i.e., near-crashes and minor crashes) in the Netherlands with the aim to proactively identify potential crash partners, crash patterns, and crash risk increasing factors. To this end, twenty-eight participants used a speed-pedelec in daily traffic, equipped with a forward and a backward facing camera, for two to three consecutive weeks. In a total of 227 h of video footage in which a distance of 6584 km was travelled, 115 conflicts were identified of which 114 were near-crashes in which evasive actions were performed to avert a crash, and one was a minor crash. The most frequent conflict partner were bicycles (51 %), followed successively by cars and vans (28 %), pedestrians (12 %), powered two-wheelers (5 %) and animals (3 %). One conflict was with a truck. With conventional bicycles, most conflicts occurred in crossing maneuvers (36 %) and when the speed-pedelec and bicycle were travelling in the same direction (36 %). Also, with cars and vans, most conflicts occurred in crossing maneuvers (63 %). The case-cohort analyses in which characteristics in conflicts and characteristics in randomly selected moments of the same participant were identified, showed conflict risks to be high if: (1) bicycles or cars were in the proximity of the speed-pedelec but was substantially higher for bicycles than for cars (OR = 43.28, 95 % CI = [16.85-111.17] and OR = 22.43, 95 % CI = [7.59-66.28] respectively), (2) speed-pedelecs overtook other road users which were mostly bicycles (OR = 17.25, 95 % CI = [7.58-39.24]), (3) the speed-pedelecs travelled on bicycle facilities (both legally or illegally) (OR = 1.81, 95 % CI = [1.08-3.03]), and (4) speed-pedelecs rode near or at an intersection, OR = 3.94, 95 % CI = [2.42-6.43]. These findings suggest that conflict risks are higher when speed-pedelec riders make use of bicycle facilities than when they ride on the roadway for cars. However, the consequences of crashes with motorized vehicles on the roadway will probably be more severe for speed-pedelec riders than with bicycles on the cycle path. This study further illustrates the value of naturalistic conflict observations for assessing the safety implications of innovations proactively.