The Electronic Road Pricing (ERP) system is an electronic toll collection scheme adopted in Singapore to manage traffic by way of road pricing, and as a usage-based taxation mechanism to complement the purchase-based Certificate of Entitlement system. There are a total of 93 ERP gantries located throughout the country, along expressways and roads leading towards the Central Area. As of February 2023, there were a total of 19 ERP gantries in operation, as compared to 77 in 2020 before the COVID-19 pandemic in Singapore.
ERP gantry along the Bukit Timah Expressway.
An IU installed in a Comfort Taxi-managed Hyundai Sonata CRDI
A three-piece On-Board Unit (OBU) installed on a private car in Singapore
An ERP gantry in operation.
Electronic toll collection
Electronic toll collection (ETC) is a wireless system to automatically collect the usage fee or toll charged to vehicles using toll roads, HOV lanes, toll bridges, and toll tunnels. It is a faster alternative which is replacing toll booths, where vehicles must stop and the driver manually pays the toll with cash or a card. In most systems, vehicles using the system are equipped with an automated radio transponder device. When the vehicle passes a roadside toll reader device, a radio signal from the reader triggers the transponder, which transmits back an identifying number which registers the vehicle's use of the road, and an electronic payment system charges the user the toll.
E-ZPass tollbooths, like this one on the Pennsylvania Turnpike in Bensalem Township, Pennsylvania, use transponders to bill motorists.
Many ETC systems use transponders like this one to electronically debit the accounts of registered cars without their stopping.
Transponder used in Chile for some expressways
ETC Built-in Onboard device in a Nissan Fuga vehicle in Japan