Electronic Road Pricing: Developments after phase I

The Land Transport Authority (LTA) launched the Electronic Road Pricing (ERP) system in April 1998 as a new way to manage traffic congestion. Phase I was completed in September 1998 with the activation of ERP for East Coast Parkway (ECP), Central Expressway (CTE), Pan-Island Expressway (PIE) and the city area. The number of ERP gantries in operation has since increased to 71, up from 33 at the end of 1998.1 Improvements have also been made to the scheme since it was first introduced, including credit card payment of ERP charges and graduated fee pricing.2

Expansion of ERP Coverage
Since 1998, more expressways have been covered under the ERP system. These are the Ayer Rajah Expressway (AYE), Bukit Timah Expressway (BKE), Kallang-Paya Lebar Expressway (KPE) and Marina Coastal Expressway (MCE).3 The ERP network has also extended to arterial roads outside the city in response to the heavy city-bound traffic on these roads. The first few roads to come under the ERP umbrella are Thomson Road, Bendemeer Road and Kallang Road.4

In 2005, ERP was used for the first time to manage the congestion caused by motorists heading back to their suburban homes after work. A new gantry that operated only in the evenings was installed on the north-bound CTE.5 Since 2005, evening ERP has been applicable for the ECP, MCE, AYE and the central business district (CBD) to target the evening peak hour traffic.6

Major enhancements
Graduated fee pricing
After observing that motorists often sped up just before the start of a time period with higher ERP rates, or slowed down just before lower rates kicked in, LTA introduced a graduated fee pricing in 2003. The objective was to reduce the incentive for such behaviour by moderating the sharp changes in rates between two successive time periods. This was done by implementing five-minute buffer periods during which the ERP rate would be midway between the rates of the two successive periods.7

85th-percentile speed measurement method
Every quarter, LTA reviews the traffic conditions on roads where the ERP system is in operation. After the review, it adjusts the rates where necessary so as to achieve optimal traffic flow on these roads.8 It also monitors other roads closely to identify new locations where congestion levels warrant ERP. When LTA first introduced the system, it said that ERP would be activated or the charges at existing gantries would be raised when average speeds fell below the threshold levels of 45 kmh for expressways and 20 kmh for arterial roads. However, the use of average speeds to determine when ERP rate changes were needed could create "stop-start" conditions on the roads easily. Thus, since July 2008, LTA has used the 85th percentile speed method to measure actual traffic conditions. With this, “motorists will be assured of smooth travel on ERP-priced roads at least 85 percent of the time”.9

Orchard Road cordon
As the Orchard Road area is primarily a shopping destination, its traffic pattern differs from that of the rest of the city centre. The road experiences heavier traffic later in the day, after the retail outlets have opened. To better reflect and manage the traffic conditions of this area, the ERP rates here have been set separately from those for other parts of the CBD since October 2005. To make this possible, LTA first demarcated the Orchard Road cordon, then sealed it off by adding new gantries. Unlike for the rest of the CBD, there is currently no ERP for the Orchard Road cordon on weekday mornings.10

Improved in-vehicle unit
LTA has introduced a second-generation in-vehicle unit (IU) that offers several improvements over the old model. For example, the new IU can accept both contact and contactless stored-value cards, whereas the previous model accepted only contact cards, specifically the NETS CashCard. Another new feature is that it can automatically top up a card that registers insufficient funds when the vehicle passes through an ERP gantry. The improved IU was rolled out to new motorcycles and installed in all other new vehicles from 2009 onwards. Owners of existing vehicles can purchase the new device or continue to use the earlier model.11

From 2008, cardless ERP payment systems, such as EZ-Pay, MotorPay and vCashCard, were introduced to allow motorists to pass through ERP gantries without a CashCard in their IU. With these systems, all the charges are billed to a registered credit card.12

Sep 1999: ERP extended to AYE and arterial roads outside the city.
Feb 2003: Graduated fee pricing introduced.
Sep 2003: New scheme launched for foreign-registered cars to give added convenience to foreign travellers – instead of installing or renting an IU, motorists can opt to pay a fixed daily ERP fee.13
Aug 2005: Evening ERP introduced for home-bound traffic leaving the city.
Oct 2005: Separate ERP cordon for Orchard Road area is implemented.
Oct 2007: KPE partially opened, with one new ERP gantry activated at the south-bound KPE exit into west-bound ECP.14
Nov 2007: ERP kicks in on BKE.15
Mar 2008: Government announces that new signboards, known as the Rates Variable Message System, will be installed at the top of gantries to prominently display the prevailing charges for various vehicle types. This is an improvement over the existing roadside panels, which motorists sometimes find too difficult to read.16
Jul 2008: Singapore River Line is activated, comprising five new gantries along the Singapore River, to reduce evening through-traffic. LTA also implements the 85th-percentile speed measurement method.17
Aug 2008: Installation of next-generation IUs on new motorcycles commences.
Sep 2008: KPE is fully opened, with a total of 16 ERP gantries installed, the largest number of gantries on a single road. However, the gantries would only be activated when congestion builds up and travel speeds fall below 45kmh.18
Nov 2008: New scheme introduced to allow ERP charges incurred by motorists to be billed to their credit cards, as an alternative to having the charges deducted from the CashCard in the IU.

Valerie Chew

1. Karamjit Kaur, “ERP to Be Extended in September,” Straits Times, 21 April 1999, 3 (From NewspaperSG); “ERP Rates and Gantries,” Land Transport Authority, accessed 31 January 2017.
2. Karamjit Kaur, “ERP Discount to End Gantry Waiting Game,” Straits Times, 29 January 2003, 3; Maria Almenoar, “Credit Cards Can Be Used for ERP,” Straits Times, 25 October 2008, 37. (From NewspaperSG)
3. Land Transport Authority, “ERP Rates and Gantries.”
4. Kaur, “ERP to Be Extended in September.” 
5. Christopher Tan and Goh Chin Lian, “ERP Cordon in Orchard Road,” Straits Times, 28 May 2005, 1. (From NewspaperSG)
6. Land Transport Authority, “ERP Rates and Gantries.”
7. A. P. Gopinath Menon and K. K. Chin, “ERP in Singapore – What’s Been Learnt from Five Years of Operation,” February 2004.
8. Menon and Chin, “ERP in Singapore.”
9. Land Transport Authority, “Five New ERP Gantries and New ERP Criteria to Apply to the Central Business District from 7 July,” 18 June 2008; ERP,” Ministry of Transport, accessed 11 December 2017; Maria Almenoar, “Higher ERP Rates and New Gantries from July 7,” Straits Times, 18 June 2008, 1. (From NewspaperSG)
10. “Orchard Rd ERP Rates Will Be Different,” Today, 29 September 2005, 6. (From NewspaperSG)
11. Christopher Tan, “New IU Promises Smoother ERP Rides,” Straits Times, 15 July 2008, 27. (From NewspaperSG)
12. Almenoar, “Credit Cards Can Be Used for ERP”; Adrian Lim, “EZ- Pay Removes Hassle of Topping Up Cashcard,” Straits Times, 17 August 2016, 3. (From NewspaperSG)
13. “Drivers of Foreign Cars Can Opt for Fixed ERP,” Straits Times, 29 August 2003, 11. (From NewspaperSG)
14. Vincent Leow, “Singapore’s New Highway,” Straits Times, 24 August 2007, 50. (From NewspaperSG)
15. Samuel Ee, “ERP to Cover Three More Stretches of Expressway,” Business Times, 24 August 2007, 10. (From NewspaperSG)
16. Almenoar, M. (2008, March 7). ERP Gantries to Flash Charges By Year-EndThe Straits Times, p. 68. Retrieved from NewspaperSG.
17. Almenoar, “Higher ERP Rates and New Gantries.” 
18. Maria Almenoar and Yeo Gim Lay, “Relief at Last, as KPE Opens,” Straits Times, 20 September 2008, 95; Tan Hui Leng, “16 Gantries on KPE for Safety,” Today, 28 August 2008, 12; Desmond Ng and Kelvin Chan, “KPE By Numbers,” New Paper, 20 September 2008, 12 (From NewspaperSG); “New ERP Gantry to Be Activated, Revised ERP Rates from May 8,” Today, 28 April 2017.

Further resources
A. P. Gopinath Menon and K. K. Chin, “The Making of Singapore’s Electronic Road Pricing System,” in International Conference on Transportation Into the Next Millennium: Proceedings, 9-11 September 1998 (Singapore: Centre for Transportation Studies, Nanyang Technological University, 1998), 179–80. (Call no. RSING q388.114 INT)

Leong Wee Keat, “ERP: New Gantries, Rates Next Week,” Today, 30 October 2007, 2. (From NewspaperSG)

M. A. Do and J. T. Ong “Evaluation of an Electronic Road Pricing System Designed for the Singapore Multi-Lane Road Environment,” in International Conference on Transportation Into the Next Millennium: Proceedings, 9-11 September 1998 (Singapore: Centre for Transportation Studies, Nanyang Technological University, 1998), 201–10. (Call no. RSING q388.114 INT)

M. Yamamoto, et al., “Multi-Lane Electronic Road Pricing System in Singapore,” in International Conference on Transportation Into the Next Millennium: Proceedings, 9-11 September 1998 (Singapore: Centre for Transportation Studies, Nanyang Technological University, 1998), 191–200. (Call no. RSING q388.114 INT)

Maria Almenoar, “ERP Cuts Traffic While Keeping Orchard Buzz,” Straits Times, 12 May 2008, 26. (From NewspaperSG)

Maria Almenoar, “Only 1 of 6 Planned ERP Gantries to Be Built,” Straits Times, 27 September 2008, 15. (From NewspaperSG)

The information in this article is valid as of 2019 and correct as far as we are able to ascertain from our sources. It is not intended to be an exhaustive or complete history of the subject. Please contact the Library for further reading materials on the topic.

Electronic Road Pricing System--Singapore
Urban transportation policy--Singapore
City traffic--Singapore