Effects of Bike Lanes on Driver and Bicyclist Behavior

The influence of bike lanes on the lateral positioning of bicycles and autos is examined through filmed observations on a variety of urban streets both with and without bike lanes. Supporting data from three streets sampled before and after the construction of bike lanes aid exploration of the effects of different street widths and vehicle speeds in interaction with bike lanes. Results indicate reduced variability in auto passing behavior on bike lane streets, i.e., fewer wide swerves and close passes by autos overtaking bicycles. The average (mean) lateral separation between bicycles and overtaking cars is not affected by the provision of bike lanes. The data suggests that on certain streets autos and bicycles traveling alone are confined to narrower bands with considerably less overlap when a bike lane is provided, and as a corollary, that auto displacement during the passing maneuver is smaller on bike lane streets.