The Singapore Area Licensing Scheme (ALS), (Malay : Skim Perlesenan Kawasan Singapura) was a road pricing scheme introduced in 1975 to 1998, charged drivers who were entering downtown Singapore, and thereby aimed to manage traffic demand. This was the first urban traffic congestion pricing scheme to be successfully implemented in the world. This scheme affected all roads entering a 6-square-kilometre area in the Central Business District (CBD) called the "Restricted Zone" (RZ), later increased to 7.25 square kilometres to include areas that later became commercial in nature. The scheme was replaced in 1998 by the Electronic Road Pricing.
The introduction of congestion pricing was one of a number of anti-congestion policies implemented in Singapore since the 1970s, in recognition of the country's land constraints, need of economic competitiveness, and to avoid the traffic gridlock that chokes many cities in the world. One key aspect of demand management in Singapore is the restraint of vehicle ownership, either through the imposition of high ownership costs or restriction on the actual growth of the car population. These measures have included high annual road tax, custom duties and vehicle registration fees. Besides fiscal deterrents, supply of motor vehicles was regulated since 1990, when a Vehicle Quota System was introduced. These high initial buy-in charges are considered as the price motorists pay for the luxury of owning a car and to cover part of the fixed costs associated with scaling basic road infrastructure. Then, use-related charges, such as fuel taxes (50% of final sale price), ALS or high parking rates are utilised by public authorities to further constraint travel. In parallel to the whole spectrum of road pricing measures, the government has invested heavily in public transport and implemented a park-and-ride scheme, with thirteen fringe car parks, hence providing car users a real alternative to switch travel modes. In summary, Singapore's urban and transport strategy allowed the users to have pro-transit "carrots" matching auto-restraint "sticks", and as a result, despite having one of the highest per capita incomes in Asia, 32% of Singaporean households owned cars in 2010.
The ALS was first formulated and designed in 1973, under the leadership of a high level inter-ministerial committee, which recommended policies and measures to improve the urban transport situation back then. The ALS scheme was implemented only after a one-year public dialogue and some modifications were made based on the public's feedback. As detailed above, the ALS was sold as part of an overall package of road pricing measures and public transportation improvements that helped to gain public support.