The Scottish Executive has made a firm commitment to re-aligning the A95 at Gaich, near Grantown, which would allow the Strathspey Railway to be extended.
The plan is for the railway line to be extended to Grantown
The £2.9m scheme will involve the line going under the road.
Transport Minister Tavish Scott said the project would be ready for construction by 2008/9 and funding had been allocated for 2009/10.
Strathspey MP Danny Alexander said a rail link between Aviemore and Grantown would be good for tourism.
The Strathspey Railway is a restored steam railway using part of the old route from Aviemore to Forres.
It currently carries passengers between Aviemore, Boat of Garten and the Broomhill on the banks of the Spey, about 3.5 miles south of Grantown on Spey.
The timetable announced will allow sufficient time for the Strathspey Railway Company to secure a Light Railway Order, which is necessary for the extension to go ahead, and to raise funds for other elements of the project.
The decision follows a meeting in Aviemore in May where the Strathspey Railway Company and other stakeholders put their case to the minister.
Mr Alexander said he was "absolutely delighted".
"It is great to be able to help ensure that this vitally important project for Strathspey goes forward," he said.
The Strathspey Railway runs from Aviemore to Forres
"The Strathspey Railway is one of the most popular tourist attractions in the area and already brings significant economic benefit to Badenoch and Strathspey.
"Extending the railway to Grantown on Spey will significantly increase its potential as well as delivering a much-needed economic boost to Grantown."
He added that a rail link between Aviemore and Grantown would also offer longer term possibilities in terms of improving public transport.
"There is clearly a lot of work still to do in terms of planning and raising funds but with a clear commitment on the road front we now have the green light to go forward," he said.
A bus service, the Grantown Special, will be running to the town from Broomhill from 12 July to 30 August as a pilot scheme.