Outer Ring Road System

Outer Ring Road System
Outer Ring Road System is labelled in double navy blue line
;">Route information
History: Introduced in 1994
;">Major junctions
West end: Ayer Rajah (AYE)
East/South end: Tampines (Eastwards)
Marine Parade (ECP) (Southwards)

The Outer Ring Road System, or more commonly known as ORRS, is a network of major arterial roads in Singapore that forms a ring road through the towns along the city fringe. The ORRS is a semi-expressway, just like the West Coast Highway. Since 1994, roads along the ORRS have been upgraded in stages to provide a smoother route to travel across the island. Roads and interchanges along the ORRS are constantly being upgraded to cater to the ever increasing traffic demand.


The route of the ORRS forms a semi-circle shape, connecting several expressways and major arterial roads. Travelling from west to east in a clockwise direction, the route begins at Queenstown with a connecting to the Ayer Rajah Expressway. The route continues northward through the residential areas of Bukit Timah via Farrer Road and Adam Road, with the first connection to the Pan Island Expressway. The route continues east through Bukit Brown, Toa Payoh, Bishan and Bartley, via the MacRitchie Viaduct and Lornie Viaduct and a connection to the Central Expressway. From here, the route splits into two direction: one travelling south to Eunos and Marine Parade through a series of roads ending with a connection to the East Coast Parkway, with a second connection to the Pan Island Expressway, and another travelling eastwards to Kaki Bukit and Tampines through a series of viaducts.


With the ORRS, traffic volume on city-bound roads will be reduced. It also provides an alternative route east-west travel for motorists without going through the city. Since ORRS is extensively linked to expressways and other arterial roads, such as Bukit Timah Road, motorists can get from one traffic route to another easily.

Upgrading projects

The first upgrading project started in 1994, with two intersections along Farrer Road being the first to be upgraded. The upgrading projects had to be carried out in stages in order to minimise disruption to traffic. The completion of the Portsdown Flyover, Queensway Flyover and Queensway Underpass marks another milestone in the realisation of the ORRS. The Farrer Road section of the upgrading project is expected to be completed by 2009.

Interchange along ORRS

Road name Interchange with 1 Type Remarks Name of interchange
Portsdown Avenue Ayer Rajah Expressway SPUI Start of ORRS going eastbound; end of ORRS going westbound. Portsdown Flyover
Queensway 3-way From Portsdown Avenue, it goes straight towards Queensway northbound and the ORRS continues from there. Queensway Flyover
Queensway Commonwealth Avenue SPUI - Queensway Underpass
Margaret Drive LILO Can only be accessed by traffic travelling westbound. -
Farrer Road Holland Road Three-level diamond To go from Queensway to Farrer Road, one can drive through the Farrer Underpass. Farrer Underpass, Holland Flyover
Bukit Timah Road Three-level diamond Bukit Timah Road travels westward only, access the Farrer Flyover to stay on the ORRS. Farrer Flyover, Bukit Timah Underpass
Adam Road Dunearn Road Three-level diamond Dunearn Road travels east bound only, access the Farrer Flyover to stay on the ORRS. Farrer Flyover, Dunearn Underpass
Pan Island Expressway Parclo - Adam Flyover
Lornie Road To go from Adam Road to Lornie Road, one can drive on Adam Flyover. Adam Flyover
Thomson Road To go from Lornie Road to Braddell Road, one can drive on MacRitchie Viaduct. Marymount Flyover, MacRitchie Viaduct, Lornie Viaduct
Braddell Road Bishan Road Semi-directional T Bishan Flyover offers a non-stop drive through this interchange. Bishan Flyover
Lorong 6 Toa Payoh Trumpet - Toa Payoh North Flyover
Bishan Street 11 LILO Can only be accessed by traffic travelling eastbound. -
Lorong 8 Toa Payoh Slip lane Lorong 8 Toa Payoh only allows traffic to travel westbound only. Vehicles are not permitted to leave the ORRS here. -
Central Expressway, Lorong Chuan 3-level SPUI Braddell Underpass offers a non-stop drive through this interchange. Braddell Underpass, Braddell Flyover
Upper Serangoon Road Three-level diamond To go from Braddell Road to Bartley Road, one can drive through Bartley Underpass. This interchange is Singapore's first four-tier interchange, with, from highest to lowest, Upper Serangoon Viaduct, Upper Serangoon Road, Bartley Underpass and North East Line tunnel. Bartley Underpass, Upper Serangoon Viaduct
Bartley Road Serangoon Avenue 1 3-way - -
Upper Paya Lebar Road Box From here, the ORRS splits into two directions: towards Marine Parade and Towards Tampines. -
Towards Marine Parade
Bartley Road East Hougang Avenue 3 SPUI To continue southwards along the ORRS, one needs to turn into Hougang Ave 3. -
Hougang Avenue 3 Airport Road Box - -
Eunos Link Ubi Avenue 2 & Kaki Bukit Avenue 1 Box - -
Bedok Reservoir Road 3-way - -
Jalan Eunos Pan Island Expressway SPUI - Eunos Flyover
Eunos Crescent 3-way - -
Sims Avenue & Sims Avenue East Box Sims Avenue & Sims Avenue East travels eastbound only. -
Changi Road Box Changi Road travels westbound -
Still Road Joo Chiat Place Box - -
Koon Seng Road & Lorong J Telok Kurau Box - -
East Coast Road Box - -
Still Road South Marine Parade Road Box - -
East Coast Parkway Trumpet, Parclo Start of ORRS leading westbound; end of ORRS leading eastbound. Marine Parade Flyover
Towards Tampines
Bartley Road East Hougang Avenue 3 SPUI To continue eastwards along the ORRS, one needs to enter the Bartley Viaduct. Bartley Viaduct
Airport Road SPUI Only motorists travelling westbound can only enter and exit to Airport Road. Bartley Viaduct
Bedok North Road Directional T To go from Bartley Road East to Tampines Avenue 10, one can drive on Kaki Bukit Viaduct. Kaki Bukit Viaduct
Tampines Avenue 10 Tampines Avenue 1 Box, Directional T Start of ORRS leading westbound; end of ORRS leading eastbound. -

^Note 1 : Only expressways, arterial roads and major roads will be mentioned. Minor roads will not be mentioned.

See also


  • Outer Ring Road System (ORRS)
  • Opening Of Extension Of Queensway To The AYE And Queensway/Commonwealth Avenue Interchange
  • Speech by Mrs Lim Hwee Hua, Minister of State for Transport and Finance, at the opening of the extension of Queensway to Ayer Rajah Expressway and Queensway Underpass on Saturday, 13 August 2005, 9.15 am
  • Braddell Road/Thomson Road/Lornie Road Flyover to open in July
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