Construction of a new twin-bore tunnel to carry a dual two-lane road under the Thames between North Greenwich and Silvertown. The tunnel will relieve the nearby Blackwall Tunnels which run significantly above their capacity for much of the day and are prone to severe congestion and disruption. The scheme is being funded by borrowing against the receipts of a new toll which will apply to both the new Silvertown Tunnel and the existing Blackwall Tunnel, the cost of which will be matched with the tolls on the crossing at Dartford.
The road will branch off the existing A102 Blackwall Tunnel Southern Approach road, passing underneath Edmund Halley Way and crossing the river approximately on the line of the Emirates Cable Car. It will surface just north of the DLR tracks parallel to Silvertown Way. The existing roundabout beanath Silvertown Way, connecting the A1020 Lower Lea Crossing and Tidal Basin Road, will be enlarged and signalised to provide a terminus for the new road, with a route cut directly through the roundabout connecting the tunnel and the Lower Lea Crossing.
Within the tunnel, one lane in each direction will be restricted to buses and HGVs, with the other for general traffic. This reflects Transport for London's intention that it will serve heavy lorry traffic that cannot currently use Blackwall because of height restrictions and help to provide an improved bus service across the river.
The new tunnel will be built using the "submerged tube" method, in which pre-cast tunnel segments are floated into position on the river and then sunk into a dredged channel. Once these have been connected the walls between them are knocked through to form a continuous tunnel and the channel is covered over.
Contracts have now been signed by TfL for the construction of the tunnel.
With thanks to Andy Hellawell for information on this page.