Caught in stop and go traffic at night for 45 minutes. Car started moving forward even though my foot was only on the brake pedal. My first thought was I'd accidentally pressed both the brake and gas pedals, but I could see my foot on the brake pedal since the under-dash area is lit in the Premium model. It happened for about one minute the first time, then happened again a couple minutes later. I hit the bumper of a tour bus during the second instance at about two mph. The tour bus driver apparently didn't notice the hit and changed lanes a few minutes later. I didn't see any damage to the tour bus, but my license plate bracket and license plate were bent, and the middle part of my bumper didn't snap back together correctly. The Ford dealer was unable to duplicate the problem, and the brakes and vacuum pressure module didn't show any leaks. The service advisor said it was impossible for the transmission to engage without pressing the gas pedal, but I suspect the 10-speed transmission since the engine rpm didn't appear to change. There were no warning lights before or after the incident and the service advisor said no codes had been set. In retrospect I should have tried putting the transmission in neutral, used the emergency brake,or turned off the ignition (but a tractor trailer was about ten feet behind me).