Plans are being considered for a fixed link across Loch Linnhe from Nether Lochaber to Ardgour, on the west coast.
The Corran Ferry, which transports more than half a million passengers every year, could be replaced within 20 years.
Work on a Scottish Transport Analysis Guide, known as a Stag appraisal, is already under way, with an initial report due to go before board members of Highlands and Islands Transport Partnership, Hitrans, at the end of this month.
Partners – including Hitrans, Highland Council and Highlands and Islands Enterprise – see the Stag appraisal as the key aspiration for the Highlands over the next two decades.
Hitrans partnership director, Ranald Robertson, said: “We have a Stag appraisal for Corran in our business plan to make a proper assessment of the route.
“We are looking at every solution – that includes a tunnel and fixed link, as well as the continued replacement of the ferry.
“A fixed link is a very attractive proposal for the route – but we will need to consider all the options highlighted as part of the appraisal.
“This is the second busiest route for vehicle movements in Scotland and presents a number of challenges.”
The council, who will appoint a Corran ferry project development officer to a post in May, said renewing the current ferry was of immediate concern to the local authority.
However, local councillor Andrew Baxter said he was looking beyond the immediate renewal of the vessel. He said: “The wider issue is what we do in the long term.
“Hitrans are committing a Stag appraisal and making a fixed link at the Corran Narrows is a priority for the next 20 years, it is a likely long-term solution.
“Even if the money was there today, we would not be able to get a fixed link for ten years – so this is the best way to move forward.
“There is a real opportunity for the Corran Narrows to be opened up. What we need to do now is talk to passengers about what they want.”
A spokesman for Highlands and Islands Enterprise said: “The Corran to Ardgour link is an important service well-used by local people and by the many visitors who come to this part of the west Highlands.
“We are aware of the need to review and appraise the different options for the future of the link, and we look forward to engaging with Highland Council and Hitrans on this.”
Ewen MacLean, chairman of Ardgour Hall Committee said: “All we want is a sustainable affordable solution.”