A master plan for major development along the A96 between Inverness and Nairn is nearing completion.
The A96 is one of the main routes to the Highlands
Proposals being considered by Highland Council include doubling the size of Nairn, two new towns and drawing water supplies from Loch Ness.
The authority will also have to build 13 new schools.
A final plan - which is being drawn up by council officials and consultants - will go before councillors in January and then out to public consultation.
The A96 corridor has been earmarked as the location for a new Inverness College campus.
Among the proposals are new towns at Tornagrain and Whiteness, with a combined population of 14,000.
Inverness will expand eastwards increasing the population by 7,000, while Nairn will double its population to 18,000.
The cost of upgrading roads, rail, electricity and water and sewerage services will run to hundreds of millions of pounds.