The Strategic Transport Projects Review (STPR) sets out the future investment programme for transport in Scotland over the next 20 years.
The managed crossing strategy for the Forth Replacement Crossing, which takes into account the existing bridge, is expected to save around £1.7bn on the original estimate of £3.2bn to £4.2bn.
"We strongly welcome today’s announcement that the new bridge is on track for completion by 2016 and confirmation of the continuing role for the existing bridge as a dedicated public transport crossing," said Forth Estuary Transport Authority convener Tony Martin.
"The existing bridge faces major maintenance challenges over the next few years, but today’s announcement helps greatly by allowing us to plan major contracts against the certainty that an alternative crossing will be in place by 2016."
The project remains on schedule to start construction in 2011 and open in 2016. Transport minister Stewart Stevenson confirmed the Forth Replacement Crossing project will be taken forward via a Parliamentary Bill by the end of next year.