Thanks for chiming in Brent. You are definitely right there. It's better to leave early and pace yourself than wait until the last minute and rush.
Some drivers might find they are not given enough time to make things happen. Let dispatch know up front that you can't make it by the delivery time and give an eta. Make sure you have a record of this exchange in case they want you to take it anyway.
Keep records and if someone gives you beef about it, let them know that you value your license and safety and your tardiness was not due to your own fault.