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Outer Circular Highway


The outer Circular Highway (OCH) is located in the Colombo Metropolitan Region and passes through two administrative districts, namely Colombo and Gampaha. This highway runs around 20 km away from the City centre of Colombo, connecting radial routes and has a total length of 29.2 km. The northern end of the highway is located at Kerawalapitiya on Colombo-Katunayake Expressway and the southern end is located at Kottawa on Colombo-Ratnapura-Wellawaya-Batticaloa (A004) road where Southern Expressway meets OCH.

The OCH is to be developed as a 4-lane Highway with provision for future expansion to 6-lanes. The design speed of the Highway is 100 kmph.

The expressway is implemented in three phases as given below;
Phase - 1 Section from Kottawa to Kaduwela
11.0 km
Phase - 2 Section from Kaduwela to Kadawatha
8.9 km
Phase - 3 Section from Kadawatha to Kerawelapitiya
9.3 km
Total length:
29.2 km


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OCH Map as at 01 October 2013
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 Project Objectives
  1. To minimize traffic congestion and encourage development away from the highly populated urban areas in the Western province achieving better balance for growth.
  2. To provide an effective bypass for North-South bound traffic and to reduce through-traffic in the city of Colombo.
  3. To provide passenger transport to destinations in a minimum time period.
  4. To provide a quick passenger and good transport facility from airport.

Anticipated Benefits

  1. To encourage foreign investors by reducing travel time by improving infrastructure facilities.
  2. To minimise environmental impacts created by burning of fuel due to traffic congestion.
  3. To encourage the development of current or future growth centres by providing connections in between. 
  4. Servicing of relatively short-distance trips between existing and future growth centres.
  5. Quick development of interchange areas will increase property value and creation of new employment opportunities.

Project Detail of Outer Circular Highway Project

Road Name
Length (km)
Total Estimated Cost
(Rs. Mn)
Date of Commencement
Anticipate Date of Completion
Outer Circular Highway - Phase 1
01 Dec.2009
May 2014
Outer Circular Highway - Phase 2
09 Jan. 2012
08 Jan. 2015
Outer Circular Highway - Phase 3


March 2014 (Tentatively)
Sep. 2017
Source: Annual Report 2012 - RDA


Last Modified Date : 08-Jan-2014