Drive your truck all the way to the finish line before the time expires. Though, you need to hurry up, you should also consider your safety when driving. The road is full of humps and mountain and you can easily end up on your back so try to observe safety while driving.
You have 10 trucks that you can use on the journey, but it doesn’t mean that you should use all of them. The others are just for reserve. The truck bounces off easily so you need to take it slow at times, but whenever you see a straight road then that is your chance to drive your truck at top speed.