Crossing the bridge: The effects of time-varying tolls on curbing congestion

• Empirical examination of the time-varying toll on the Bay Bridge.
• Toll found to decrease traffic volume and travel time during peak hours.
• Toll found to increase traffic volume during off-peak shoulder hours.

This paper estimates the traffic volume and travel time effects of the road congestion pricing implemented on the San Francisco-Oakland Bay Bridge. I employ both difference-in-differences and regression discontinuity approaches to analyze previously unexploited data for the two years spanning the price change and obtain causal estimates of the hourly average treatment effects of the policy. I find evidence of peak spreading in traffic volume and decreases in travel time during peak hours. I also find suggestive evidence of substitution to a nearby bridge and decreases in travel time variability. In addition, I calculate own- and cross-price elasticities.