A new road tunnel under the River Thames in east London will be ready within a decade, Mayor Boris Johnson was due to announce on Thursday.
With a capacity of 2,400 vehicles an hour in each direction, the link will relieve pressure on existing tunnels at Blackwall and Rotherhithe to the west.
The tunnel, to be built between Greenwich Peninsula and Silvertown in the historic Royal Docks near City Airport, will support regeneration and the area could benefit with up to 13,000 new jobs and 24,500 new homes, Johnson said.
Transport for London will begin preliminary consultation work on the Silvertown Tunnel in February.
Johnson's office said he was also due to announce, at a speech to local government leaders, that a new ferry crossing between Beckton and Thamesmead at Gallions Reach will be open for traffic by 2017.
East London has historically been one of the most deprived areas of the capital and a lack of river crossings has hampered businesses in the area.
Successive Labour and Conservative governments have made regenerating east London a priority and it is now expected to accommodate 40 percent of London's population growth until 2031, equating to 400,000 people.
The 2012 London Olympic Games will also be hosted predominantly in east London.
Johnson, who faces a mayorship re-election contest in May against his Labour adversary Ken Livingstone, was due to stress how public sector investment can be successfully achieved through partnership with private sector funding.
London has already used public-private partnerships to improve transport links, including Barclays bank sponsorship for a large cycle hire scheme and a contribution by the Emirates airline towards a cable car crossing over the Thames.
(Reporting By Drazen Jorgic; Editing by Steve Addison)