The zombie apocalypse had begun and you are trapped in the city with your truck. The zombies are out to get you as they want to eat you alive and possibly infect you with their disease and turn you into one of them.
Kill all of the zombies that runs across you by hitting them with the truck. However, don’t ever ram inot other cars or trucks as it will damage your truck. There are some wrenches on the road, which are good for repairing the truck. Use the wrench to repair your truck so you can continue on with the journey and not have the zombies catch up to you.