On Wednesday, our 2021 Tesla Y - which we have LOVED driving for the last 3 years - took off on its own while I was sitting in traffic - where traffic was at a standstill, and the max speed was probably 4 MPH. Construction ahead had closed a lane, so there was a massive back-up and cars were creeping along each time the traffic light ahead turned green.) As any Tesla owner will tell you, the best way to slow down is to remove your foot from the gas pedal, and the car will slow down and come to a stop on its own. That had always been the case for our vehicle until Wednesday. Shockingly, for no reason at all, the car massively accelerated. I slammed on the brakes, but the brakes did not slow or stop the car. Luckily, the car in front of me was only 2 - 3 car lengths away, so my Tesla which was rapidly gaining speed stopped only when it crashed into that car. I have relatively minor injuries, but I am sure I would have been killed and/or killed others if not for the vehicle in front of me forcing my car to stop. After the crash, we flat-bedded the car to a Tesla-approved auto body shop. Our insurance adjuster will be inspecting the car on Monday. We will make the vehicle available for inspection. I am still shaken from this traumatic experience. I have never had a car accident (but for a fender bender over 40 years ago). Moreover, I have spent my life working in public service (govt, elected officials and nonprofits). I am determined to make sure that this safety problem