The mayor of London's office has said it will know in a week whether the Hammersmith Flyover in west London can be reopened to traffic while critical repairs are carried out to strengthen it.
It gave assurances that the A4 route would be in full working order by the time the Olympics start on 27 July.
Boris Johnson said it would not be shut "one day longer than necessary".
The flyover closed to traffic on 23 December when defects were found.
Tom Edwards, BBC London's transport correspondent, said that the structure was originally designed to have under-road heating, but instead years of salt and grit being used in icy conditions had eroded the cables which help support the road.
He said that to begin with there had been concern that the damage was so bad the structure would have to be knocked down.
Transport for London (TfL) said a team of 80 engineers was inspecting the extent of the damage and strengthening work was being carried out.
Andy Slaughter, MP for Hammersmith, said TfL had questions to answer including why the emergency closure had been necessary.
About 90,000 vehicles a day travel along the 900m (0.5 mile) route, which was built in the 1960s.
The closure has caused what Mr Johnson described as "traffic hell" for thousands of motorists.
He visited the flyover to inspect the work being carried out.
TfL said cameras had been inserted into the structure at 100 different points to assess the cables.
The mayor said the flyover would be "fully operational well ahead of the 2012 Games".
BBC London Travel presenter Billy Reeves said that serious congestion stretched as far as Wimbledon, Putney, Barnes, Chiswick and Tibbet's Corner on Thursday evening and Friday morning, with more people returning to work after the Christmas break.
He said: "If you commute by car through London you will need to add another hour to your journey for the foreseeable future."
TfL said an extra lane had been added to the A4 Talgarth Road to try to ease congestion, traffic signals had been re-phased and there were plans to divert traffic from the M4 to other routes if necessary.