Brain teaser

Ok this ones quite hard to work out ... only 1% of the population can do it but I bet Goose gets it straight away. Good luck!

Question:

You are behind the wheel of your car and keep a constant speed. On your left you have a drop. On your right you have a fire truck and it keeps the same speed as you. In front of you runs a pig that is bigger than your car. A helicopter is following you at ground level. Both the helicopter and the pig keep same speed as you. What do you need to do to stop?

Answer in the comments.