For a trucker, nothing is more important than delivering the cargoes safely to its destination. That is reason why they are paid anyway. If they can't do a simple task then no one will trust them anymore and they will lose customers. When that happened, they are going to lose money and their love ones will get hungry. Of course, if you are the truck driver, you don't want to go there since you have mouths to feed. That is why; it is important that you take care of the cargoes. You know that won't be easy, but for you it is more than just a job because of your commitment.
Wait till all the cargoes are loaded at the back of the truck before driving the truck as fast as you can till you reach the finish line. Each level has different requirements that you need to fill. As you progress in the game, you will notice that it gets harder and harder. The idea here is to get to the finish line before time expires. You don't want to be late with your deliveries. Try not to lose any of the cargoes, but if that can't be help than just make sure that you are able to deliver the required number of cargoes.