The Causal Effect of Cycling Infrastructure on Traffic and Accidents : Evidence from Pop-Up Bike Lanes in Berlin

This paper analyses the effects of new bike lanes on traffic volume, congestion, and accidents. In order to obtain causal estimates, I exploit the quasi-random timing and location of newly built cycle lanes. Crucially, the new cycling infrastructure replaces existing car lanes thereby reducing available space for motorized traffic. Using a variety of difference-in-differences style methods on geocoded data, I show that the construction of pop-up bike lanes significantly reduced average car speed by 8 to 12 percentage points (p.p.) and up to 16 p.p. in peak traffic hours. The results for car volume are insignificant in most specifications. Ultimately, the data do not allow for a conclusive judgment of accidents