The Marina Coastal Expressway (MCE) - Singapore's first undersea road, costliest expressway and one with the widest tunnels - will open on Dec 29, four years after the $4.3 billion project started.
The 5km expressway, at $860 million per kilometre, has a 420m section that goes under the sea-bed just south of the Marina Barrage. There are five lanes in each direction.
Linking the Kallang-Paya Lebar Expressway to the Ayer Rajah Expressway (AYE), it will allow swift east-west travel.
Drivers currently using the East Coast Parkway (ECP) to join up with the AYE can switch to the MCE from Dec 29. The ECP will be downgraded to an arterial road that serves the Marina downtown.
Unlike the ECP, which cuts through a swathe of the new CBD, the MCE hugs the coastline. Part of it is actually built on reclaimed land.
With the ECP downgrade, which includes removing a section entirely, development of the Marina downtown can be optimised, said Land Transport Authority deputy chief executive Chua Chong Kheng.
The new downtown then blends seamlessly with the old.
Several other road changes in the area will take up to the third quarter of next year to be completed. New electronic road-pricing gantries will be erected, with most in the new CBD. The LTA however, said most motorists travelling from east to west and vice versa will not pay more than they do today.