Doubts have been raised over the feasibility of a controversial tractor ban on the AWPR.
Last month, farmers demanded that transport chiefs scrap plans which would mean they would be unable to use the Aberdeen West Peripheral Route (AWPR).
Transport Scotland has given the new £750million scheme a special designation which limits the distance that farm traffic can travel, effectively prohibiting the agricultural vehicles from the road.
The National Farmers’ Union Scotland (NFUS) has demanded the organisation overturns its decision, claiming farmers have borne the brunt of the major disruption caused by the project and should be allowed to take advantage of the new route.
The transport body has been steadfast in its position so far but last night, Mearns councillor Colin Pike questioned how the ban would be implemented.
Mr Pike said: “Looking at the Highway Code and the traffic sign regulations there doesn’t seem to be a prohibition sign for tractors.
“My concern here is how this regulation is to be implemented on the AWPR, A90 trunk road, as currently agricultural vehicles are permitted on the existing A90. Who is going to enforce it and what offence would any agricultural driver be charged with?
“I’m sure people would much rather travel behind a tractor going at a reasonable pace instead of being behind one which is having to negotiate a narrow country road.”
He has now written to Transport Minister Michael Matheson seeking answers to his questions.
Union bosses have criticised the policy as it means that farmers will be unable to transport livestock from Ellon to Portlethen using a tractor.
The NFUS also argued the decision flew in the face of Scottish Government targets for reducing carbon emissions.
A Transport Scotland spokeswoman said: “Special Road restriction signs featuring this information will be erected when the whole road is fully operational. As with any public road, Police Scotland is responsible for enforcing the relevant legislation ”