Seattle is known for its ferries. Maybe a hundred cars can fit in the bowels of those huge boats. The trip time is measured in tens of minutes, perhaps even hours, so you may want to leave your car and enjoy some great views from the deck or have a beer and a sandwich at the cafe. The only thing the ferry people ask is that you set your parking brake – obviously, they really don’t want to handle a runaway car. And they even came up with a sign to help the damned foreigners to understand what’s wanted from them:
Problem is, it looks like the sign depicts the wrong kind of brake. Certainly you don’t expect me to sit all the way pressing the brake with my foot? 😉
Now, I do realize that some (American) cars do have the foot-operated parking brake, but I believe most cars have a lever between the front seats for that. So if you want to convey a message to people who don’t drive older American cars, you probably should use an image more understandable to them.