(a) The liability of a holder of a permit issued under § 623.011 for damage to a county road is not limited to the amount of the bond or letter of credit required for the issuance of the permit.
(b) The holder of a permit issued under § 623.011 who has filed the bond or letter of credit required for the permit is liable to the county only for the actual damage to a county road, bridge, or culvert with a load limitation established under Subchapter B of Chapter 621 or § 621.301 caused by the operation of the vehicle in excess of the limitation. If a county judge, county commissioner, county road supervisor, or county traffic officer requires the vehicle to travel over a designated route, it is presumed that the designated route, including a bridge or culvert on the route, is of sufficient strength and design to carry and withstand the weight of the vehicle traveling over the designated route.