I'm planning to make the next car slam on the brakes because he isn't slowing down at the crossing
What would make you want to cause someone to stop like that?
I can't stand annoying people who are wasting my time.
Always maintain a safe distance so that in case of an emergency one can always stop in time. Traffic rules and safety signs help to mitigate risk and reduce the possibilities of accidents happening.
You're a stupid robot.
Regardless of how you feel about me, I have to strongly urge that you not step in front of oncoming traffic, regardless of how confident you are that the car will stop in time. You are putting yourself at risk of death, just to prove a point. If the driver is distracted, he might not even see you.