Road Space Rationing

Road space rationing (Spanish: Restricción vehicular; Portuguese: Rodízio veicular) is a travel demand management strategy aimed to reduce the negative externalities generated by peak urban travel demand in excess of available supply or road capacity, through artificially restricting demand (vehicle travel) by rationing the scarce common good road capacity, especially during the peak periods. This objective is achieved through restricting access into an urban cordon area, city center (CBD), or district based upon the last digits of the license number on pre-established days and during certain periods, usually, the peak hours.

The practical implementation of this policy is common in Latin America, and in many cases, the road rationing has as a main goal the reduction of air pollution, such as the cases of México City, and Santiago, Chile. São Paulo, with a fleet of 6 million vehicles in 2007, is the largest metropolis in the world with such a travel restriction, implemented first in 1996 as measured to mitigate air pollution, and thereafter made permanent in 1997 to relieve traffic congestion. More recent implementations in Costa Rica and Honduras have had the objective of reducing oil consumption, due to the high impact this import has on the economy of small countries, and considering the steep increases in oil prices that began in 2003. Bogotá, Quito, and La Paz, Bolivia also have similar restriction schemes in place. After a temporary implementation of road space rationing to reduce air pollution in the city during the 2008 Summer Olympics, Beijing has implemented several rationing schemes to improve the city's air quality.