Products with time limit
Yes, the time limit(usually 10 hours or 12 hours) starts from pick-up time to drop-off time at your final returning destination. If the traffic is bad and you go over the 10 hour limit, you will be asked to pay pre-defined extra hour charges.
One way products
There will be no extra charge for one way products due to traffic. The one way price is for the driver to pick you up and drop you off at your final destination.