Electronic Road Pricing Automation of the Area Licensing Scheme (ALS) implemented in 1998 (see Area Licensing Scheme and Restricted Zones). Overhead gantry signs demarcate the Electronic Road Pricing (ERP)- control points. Based on the pay- per- use principle, the system tracks all vehicles passing through the gantry and deducts from each one a levy from a stored- value card (CashCard), inserted into a small in- vehicle (IV) unit installed on the dashboard, or in the case of motorcycles/scooters, on the handlebar. To smooth traffic flow, the levy may vary at half- hour intervals. Licence plates of vehicles that violate the rule are automatically captured by the system for follow- up enforcement.

Photo credit: Sin Kam Cheong