The 25.6 Km expressway will reduce the travel time between Kelani Bridge and Katunayake to 20 minutes.
The expressway is composed of 100 box culverts and about 40 bridges along with four inter changers at New Kelani Bridge, Peliyagoda, Ja-Ela and Katunayaka. In future it is expected to have another inter change at Kerawalapitiya once the Outer Circular Road construction work is completed.
In 2006, the Chinese government offered funding for the project from the Exim Bank and China Metallurgical Group Corporation, a Fortune 500 company was selected as the contractor.
Agreement was signed in 2008 and actual construction started in August 2009 for a contract period of 36 months at an estimated cost of US$292 million. Road Development Authority officials said that the cost of the project however increased, due to the increased scope of work and new methods adopted in addition to increased safety requirements.