The overhead and transaction costs to calculate and collect the tax can't be overly burdensome. Once a year, at tab renewal time, the vehicle should be brought

The overhead and transaction costs to calculate and collect the tax can't be overly burdensome. Once a year, at tab renewal time, the vehicle should be brought in for an odometer reading and the miles put one over the previous year should then be multiplied by it's weight or maximum rated hauling weight (or some formula using both) to determine the amount of tax owed.