Road space rationing, also known as alternate-day travel, driving restriction and no-drive days, is a travel demand management strategy aimed to reduce the negative externalities generated by urban air pollution or peak urban travel demand in excess of available supply or road capacity, through artificially restricting demand by rationing the scarce common good road capacity, especially during the peak periods or during peak pollution events. This objective is achieved by restricting traffic 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.
Traffic congestion persists despite São Paulo's municipal no-drive days based on license numbers, implemented since 1997. São Paulo downtown, Brazil.
Road Space Rationing impacts behavioral changes and may lead to the ultimate outcome, i.e. end traffic congestion. Other factors impacting these changes make it hard to isolate the singular effects of Road Space Rationing regulations.
Severe smog over Mexico City.
Traffic sign used in San José, Costa Rica, to warn drivers of the prevailing access restriction into the CBD according to license plate number by day of the week.
Transportation demand management
Transportation demand management or travel demand management (TDM) is the application of strategies and policies to increase the efficiency of transportation systems, that reduce travel demand, or to redistribute this demand in space or in time.
Evening traffic on the A1 freeway in Slovenia
Traffic congestion on Interstate 5, at Los Angeles, California
UK air travel by income quintile through time
