Exploring free riding behavior: An instrumented bicycle study on the impact of infrastructure and wind on bicycling

Understanding free riding behavior –where bicyclists are unconstrained by other road users or traffic control measures– is essential for planning efficient and appealing bicycle traffic systems. Bicyclist behavior is shaped by a combination of environmental conditions and individual preferences. This study examines free riding behavior, and identifies correlations with individual characteristics and contextual features such as infrastructure design (slopes and curves) and wind speed. We introduce a method using instrumented bicycles in a semi-controlled experiment to collect data describing the speed, power output, and heart rate of commuting bicyclists. Participants in two study populations (28 in Sweden and 29 in Germany) ride their bicycles equipped with sensors along designated routes during off-peak demand periods, enabling comparative analysis of different trip features. Results highlight significant inter- and intrapersonal variations in speed and power output along a trip. Approximately 80 percent of the variation in free riding speed and power output over a trip, and over both populations of bicyclists, is explained by gender, individual preferences, topography, curvature, crossing intersections, and wind speeds. Headwinds and uphills generally reduce speeds but bicyclists increase power output to partially offset these effects. Downhills lead to high speed variation and distinct tactical behaviors, such as braking, coasting, and accelerating. These findings underscore the complexity of bicycling behavior and quantify how bicyclists adapt to varying features of the trip.