Road space rationing
Road space rationing, also known as alternate-day travel, driving restriction, no-drive days and number coding (Spanish: restricción vehicular; Portuguese: rodízio veicular; French: circulation alternée), 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 (vehicle travel) 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 vehicle registration plate on pre-established days and during certain periods, usually, the peak hours.