Impact of traffic zones on mobility behavior in Tehran, Iran

The use of private cars has increased rapidly in developing countries, causing congestion and pollution in cities. In Iran, measures have been taken to manage the extensive automobile use in Tehran. Two downtown traffic zones were introduced: The Restricted Traffic Zone (RTZ) based on pass permission and the Odd-Even Zone (OEZ) based on license-plate number. This article investigates how and to what extent traffic zoning influences mobility behavior in Tehran. Two neighborhoods within these zones and one elsewhere were selected to compare the impact of traffic zoning on mode choice and travel time by means of regression analyses. The results show that zoning has decreased driving in both neighborhoods; although compared to the RTZ, the OEZ has had a limited impact. While car use has diminished in both neighborhoods compared to the area without restrictions, travel time has increased in the traffic zones. An explanation might be the low quality of the infrastructure for alternative modes (e.g., cycling). Tehran’s spatial functional specialization and the monocentric urban structure induce more car trips and longer travel times, regardless of traffic restrictions. Policymakers are advised to integrate restrictions on automobile use with improvements in public transport to enhance the impact of traffic zones.