The parking brake was set on a car I borrowed. I failed to see the red warning light because of the sunlight on the dash. The car moved when I shifted to drive, though it felt a bit sluggish. I drove about 3 miles up an expressway and spotted a toll booth ahead. When I applied my brakes (at about 45 mph) the pedal went all the way to the floor! My brakes had vaporized! While approaching the toll booth I had only two choices before me: smash into the concrete separator or hit the car in front which was just accelerating. Well, I knew I'd be severely injured or killed if I hit the concrete at that speed (I was in a small k-car); so I crashed into the car in front. It was being driven be a dad with 2 small girls in the back seat. VERY fortunately, no one was injured. But, I'm left with the knowledge that I could have killed someone due to my ignorance.