The Outer Circular Highway (OCH) to the City of Colombo is a new access controlled highway, linking Colombo – Katunayake Expressway (CKE) and Southern Transport Development Project (STDP). It is 10 – 15 kms away from the City Centre and 29.10 kms long in total. It will connect the North and South more quickly as a by-pass to the Colombo City and disperse the traffic from / to Colombo more effectively, resulting in easing traffic congestions in the Colombo Metropolitan area.
| Length | 8.6 km |
| Width | 4-lane access controlled Highway |
| Design Speed | 100 km/hr |
| Structure | 5.5km long Viaduct / and 2 long Bridges – With Long Span Design Review and Construction Supervision |
Nouthern Section: Kaduwela to Kadawatha (8.86 kms)
Northern Section of the Outer Circular Highway is 8.86 kms long and is to be constructed as an access controlled dual 4-lane highway including 2 Interchanges, 2 long Bridges and 5.5km long viaduct. A length of 3.19km is subject to soft ground treatment adopting Gravel Mat, Bank Drains, Geotextiles, Rock Replacement and Gravel Piles.
