Dualling the A9 road from Inverness to Perth could generate almost £1bn for the Highlands and Islands economy, according to a new report.
The road has been a source of frustration for businesses
Highlands and Islands Enterprise and transport campaign group Hitrans estimate journey times could be cut by 22 minutes.
Transport Minister Stewart Stevenson said the government was committed to a plan to upgrade the route.
Previous estimates have put the cost of dualling the stretch at £600m.
The A9 Perth to Inverness Economic Appraisal Study has predicted that 724 jobs could be created in the short-term - rising to 4,500 over 30 years.
Mr Stevenson said the report's findings were positive.
A9 IN NUMBERS
The distance from Inverness to Perth is 113.5 miles (182.6km)
According to the AA, the journey takes 2hrs 35mins
32% of A9 travellers are tourists, 11% are from the construction industry and 7% from the agriculture and manufacturing sectors, according to the new report
He said: "This Scottish Government is totally committed to the plan for dualling the A9.
"We made that commitment when we came into government, and we stand by that commitment."
Mr Stevenson said government agency Transport Scotland would be asked to identify the next part of the A9 which could be dualled in the short-term.
Future plans for the road will be looked at in next year's Strategic Transport Project Review.
Donald MacNeill, senior transport policy manager at HIE, said: "So many of our visitors - and our imports and exports - use this route and the report has demonstrated that enhancements would have a significant positive impact on the region's economy."
North businesses have in the past branded the A9 as "unsatisfactory".