ERP Gantries and Charges

Mr Lim Biow Chuan asked the Minister for Transport (a) based on the Ministry's quarterly review of traffic conditions, how many vehicles pass through the ERP gantry on the CTE south of Braddell Road during the morning peak hours from 7.30 am to 8.30 am in each of the last four quarters of the year; and (b) how does LTA compute the speed of the vehicles in determining ERP charges.

The Table below provides the average number of vehicles passing under the Electronic Road Pricing (ERP) gantry on the Central Expressway (CTE) south of Braddell Road from 7.30 am to 8.30 am in the past four quarters. Traffic volume has increased by about 15% since the completion of the CTE widening project in December 2011.

ERP rates are set based on traffic speeds. The Land Transport Authority (LTA) uses speeds obtained from Intelligent Transport Systems (ITS) devices, such as the Expressway Monitoring and Advisory System (EMAS) cameras, along the priced stretch of expressway to review ERP rates. For a period of two weeks every quarter, speeds are measured over continuous half-hour intervals during peak hours. Since 2008, the 85th percentile of speeds measured has been used to trigger ERP rate changes. This will generally assure 85% of motorists of smooth travel on ERP-priced roads.