The Scottish cabinet is expected to back plans within the next fortnight for a new Forth crossing.
The first minister is "committed" to the construction of a new crossing
Ministers are to be briefed on the condition of the existing road bridge, thought to be in need of more intensive maintenance than previously thought.
Engineering assessments and detailed reports will be considered before a decision is taken on whether to build a new bridge or construct a tunnel.
Decisions are expected within the next two weeks, possibly by Wednesday.
Last November First Minister Jack McConnell confirmed that Labour was committed to the construction of the new crossing.
Approved in principle
Further work will be needed before the executive chooses the type of bridge or tunnel it wants, the route it will take and the means of funding the work.
But the Cabinet will be asked to approve plans for a replacement crossing in principle, as well as a broad timetable for its construction.
Corrosion is a major problem with the present road bridge and its replacement has been the subject of fierce debate.
The new crossing is expected to be in place before the existing road bridge closes to traffic in 2013.
On Thursday a parliamentary debate on scrapping tolls on the Forth and Tay road bridges ended in stalemate after the parliament failed to agree a position.
Both an SNP motion calling for the abolition of the tolls, and an executive one calling for their retention, were defeated.
John McGoldrick, from the National Alliance Against Tolls, said: "The ministers who say that they want a new Forth crossing are the same people who have fought to keep tolls on both the Forth and Tay.
"The assumption must be that this new crossing would also be tolled.
"We have calculated that the return tolls for cars would be about £7.
"The ministers will be the only ones who will be able to afford to use their new crossing."