If a car is braking it rides differently from one that isn't. A car is normally rather level and leans "forward" when braking.
Besides that, YOU SHOULDNT GET IN FRONT OF ANYTHING YOU ARENT SURE IS STOPPING. If it's moving fast enough that you need this, you shouldn't be trying to get in front anyways.
Again, if you're too stupid to make sure the multiton hunk of metal is coming to a stop by all the other obvious visual markers, including watching it's speed compared to stationary objects like signs and lamp posts, then this won't do shit. People need more aweness of their surroundings, not a bunch of lights and horns because people won't pay attention.
You enter the road when it's safe, not jump in and play frogger with lights hoping to get across.