Drive your truck as fast as you can get to the finish line as soon as you can. You won’t need to drive there as fast as you can if you don’t like it since that isn’t a requirement. The time has something to do with the score. There will be more bonus points for you if you can get to the finish line before the time ends.
You need to drive fast, but that doesn’t mean that you don’t need to take the necessary precautions as you need it. You truck isn’t crash-proof, aside from that, you can also drop your cargo if you aren’t careful enough.