1) Wait until it is all clear, a cyclist or motorcycle may be overtaking the 3 cars, and you may not see it. 2) If you've been waiting at the lights for a while, do full checks, mirrors, and both lifesavers before moving off. Cyclists or motorcyclist could be filtering, up into your blind spot 3) Check mirrors, use brakes and roll off throttle to slow down. Checking mirrors so you know what is happening behind you as you slow. Brake lights warn following traffic you are slowing