The contract says three lists. Road-city-casual. Everyone knew when they bid on a road job that they took the chance that if the job was cut they would go to the bottom of the city seniority. That is the way it has always been. It is a risk you take by going to a bottom job road run. Many have passed up road runs that were newly bid, just because they didn't want to risk the chance that it would be cut and they would go to the bottom of the city board.
The contract plainly address this issue in the layoffs section, so unless you are going to renegotiate the contract, I don't see how a one list will fly?