Sri Lanka is planning to start construction on the $400m second phase of the Colombo Outer Circular Highway (OCH) later this month.

The project will be carried out in three phases and involves building a 29km long outer circular road network that will link the Colombo-Matara Expressway with the Colombo-Katunayake Expressway, currently under construction.

OCH will start from Kerawalapitiya along the Colombo-Katunayake Expressway to link the Southern Expressway crossing A4 highway at Kottawa with the main A1 Colombo-Kandy route at Kadawata.

The Sri Lankan Road Development Authority said the purpose of the new road is to reduce congestion and encourage development away from the highly populated urban areas in the Western Province, achieving a better balance for growth.

Colombo Outer Circular Highway will provide an effective bypass for north-south bound traffic and reduce through-traffic in the city of Colombo.

In addition to the Peliyagoda and Katunayake interchanges, two more at Ja-Ela and Kerawalapitiya will be connected from the expressway to the outer circular road.

Work on the LKR25bn ($219m) first phase of an 11km stretch from Kottawa to Kaduwela is has been underway since 2009, by China Harbour Engineering Company.

The last phase from Kadawata to Kerawalapitiya is estimated to cost $290m.

The Japan International Cooperation Agency (JICA) had earlier granted $630m to complete the stretch of road from Kottawa to Kadawata, according to colombopage.

Upon completion, the route will provide access to existing ‘A-class’ roads and proposed expressways at the interchanges; it will also serve as the basis for the entire network of highways and expressways in the country.

Underpasses and overpasses have been proposed for the intersecting highways, and frontage roads of 6m in width on either side of the expressway will be built wherever necessary to provide residents with access.