Reinstating a rail line between Aberdeen and Ellon could cost as much as £381m, according to new reports.
The reports, commissioned by transport body Nestrans, look at improving road and rail links north of Aberdeen.
One looks at reinstating the rail route between Aberdeen, Dyce and Ellon. It is thought a new rail service could attract 700,000 journeys per year.
A package of road improvements including new roundabouts and overtaking lanes could cost about £39m.
Nestrans chairman Peter Argyle said while the rail option would be popular, it would be significantly more expensive than the road improvements.
Nestrans will now consult with both Aberdeen City and Aberdeenshire councils after the two reports were discussed, and take a decision early next year on which option to pursue.