We use high frequency data on traffic congestion from Google Maps to measure the impact of Jakarta’s main traffic congestion reduction policy, a high-occupancy vehicle restriction policy. We find that the unexpected lifting of the policy led to a large, sudden and persistent increase in travel delay during operating hours on affected roads, with delays rising between 45-85 percent. Surprisingly, this increase in traffic was not just substitution of traffic from unaffected roads to previously restricted roads. Instead, we find that the removal of the high-occupancy vehicle restriction led to worse traffic throughout the city, both on other roads that had never been restricted and during times of the day when there restrictions had never been in place previously. The results suggest that targeted restrictions on road use can have positive general equilibrium effects on traffic throughout the city.
Hanna, Rema, Gabriel Kreindler, and Benjamin A. Olken. "Citywide Effects of High-Occupancy Vehicle Restrictions: Evidence from the Elimination of “3-in-1” in Jakarta." HKS Faculty Research Working Paper Series RWP17-008, December 2016.