ALS was sold as part of an overall package of road pricing measures and public transportation improvements that helped to gain public support. Scheme A total of 28 overhead gantries were set up along the boundaries of the RZ, including the areas surrounding Orchard Road. These gantries were monitored by auxiliary police officers who carried out visual checks and recorded any violations. Fines started at S$50. Users had to buy, in advance, a special paper licence at a cost of S$3 per day, which was sold at post offices, petrol stations, area licence sales booths or convenience stores, on a monthly or daily basis. This licence was displayed on the car windscreen or on the handle bars for motorcycles during hours of operation. Initially, they were 7.30 am to 9.30 am daily, except on Sundays and public holidays. However, it soon had to be extended to 10.15 am, to control the surge of vehicles waiting to enter just after 9.30 am. In 1989, the evening peak had to be restricted too, and in 1994, the ALS was extended from 7.30 am to 6.30 pm. In the first few years after the introduction of the ALS, passenger cars having four or more occupants, taxis, public buses and service vehicles were allowed into the zone without being charged. Carpool was exempted too, to better manage demand and to counter the belief that the scheme favoured the rich. Special carpool pick-up points were set up. In 1989 more users were required to pay the fee, as motorcycles and heavy vehicles made up about two-thirds of the traffic entering the RZ. Hence, with this review of the policy, only buses and emergency vehicles were exempted. Later, the exemption for carpools was abolished, because many private cars were picking up bus commuters just to avoid the payment. In 1980, the fee was increased to S$5, but in 1989 it was reduced back to S$3, due to the fact that now more vehicles were paying. In 1994, two levels of licence fees were established, to differentiate between daily permits and inter-peak licences. The paper licences vary in shape depending on the class of vehicle, and their colours varied from one month to another to deter fraud. The colour-coded licences also made it easier for the enforcement personnel to identify the vehicles during the restricted hours. For reason of traffic management, violating vehicles were not stopped at