A non-binding estimate charges you according to the actual weight of your shipment and the actual cost of the services that are performed. You will still go though the estimating process to determine what your shipment may cost.
To verify the weight of your shipment, the driver will weigh his trailer prior to loading your shipment. Once your shipment is on board, the driver will weigh his trailer again. All other charges will be calculated at your origin address. If there are any additional charges that are incurred during the delivery process, the driver will provide you with the additional cost. This is a rare event, but it may occur.