What do you mean "see it on a flat, open stretch of highway"? do you mean a sign for it?

Cause of the hill ahead sign it'* on.

A jake brake engages whenever the trucker lets his foot of the gas, even if it'* not downhill.

Thank you Trucks on Spike TV!

Ok..Mr. PBS... Do you know HOW IT WORKS?

Thanks for the answer. I did see the sign on the flat stretch of hwy but wondered why

Did it say "Jake Brake Use Prohibitted" or something like that?
Jake Brakes can be very loud and some places prohibit the use of them because of noise polution.

throws the exhaust gases back in to the intake which slows combustion and there for slowing the engine.

I was taught one foot driving too. Just kind of picked up the two foot habit. I don't rest my foot on the brake pedal, I just sort of hover it. I try driving one footed, but it just doesn't feel right.
I think people don't pay enough attention when they are driving. That'* the cause for the panic slam on the brakes. If they were actually keeping tabs on what was going on around them, they would be able to react quicker. Besides, panic braking is usually the last thing you should do. You lose control of the car and end up hitting something anyway.

One BARE foot.....I like to feel the pedals and driving with shoes just won't let ya do that

I can't do that. I don't like the way it feels.