Train capacity is to be increased by 6,500 seats as transport bosses try to ease disruption caused by the closure of the Forth Road Bridge.
Extra trains and buses are to be put on from Monday to ease congestion on alternative road routes between Fife and Edinburgh.
ScotRail said extra carriages and new services between Cowdenbeath and Haymarket will bring an extra 6,500 seats per day into operation, increasing passenger capacity by 40% over the period of the bridge's closure.
Around 30 Stagecoach buses will also be used as part of a park-and-ride priority service between Fife and Edinburgh, using the Ferrytoll and Halbeath sites.
The announcement was made following a meeting of the Scottish Government's resilience committee chaired by the First Minister.
It emerged on Friday that the bridge will be closed until the new year while repair work is carried out on a structural fault on the crossing.
It is estimated that around 70,000 vehicles use the bridge each day and 11-mile rush hour tailbacks were caused on Friday, the first full day of its closure.
Scotland's Transport Minister Derek Mackay described it as a matter of "national significance".
Motorists travelling into Scotland are also to be encouraged to use routes in the west of the country to ease congestion around the bridge.
Ministers are to speak to businesses hit by the closure next week to find out how they can help.
Mr Mackay said: "We know this will be a very difficult time for commuters, businesses and hauliers and we remain extremely grateful for people's patience while we work on strengthening alternative travel plans and minimise disruption during the closure period.
"Thanks to the hard work of our partners, we are able to announce significant additional resources for public transport routes between Fife and Edinburgh.
"This will include additional rolling stock on the train service that will put an additional 6,500 seats a day into operation. Thanks to Stagecoach, we will also be able to rely on an additional 33 buses, bringing thousands of extra seats into operation."
He added: "From tomorrow, commuters will be able to access a dedicated website offering detailed information on these updated travel options
"We will continue to monitor the situation closely and adapt our travel plan as required. While we are doing everything we can to ease the impact on travellers, we would urge people to do their bit by considering their travel plans in advance and making any possible contingencies.
"This could include being more flexible about your work times and locations if possible.
"We also have made contact with the main business organisations in Scotland, local authorities and enterprise areas and are working together to examine the economic and business impact and identify any practical steps that can be taken to mitigate that as much as possible."