> You are not allowed to slam on your brakes for no good reason
I never said no good reason...
>hat about if you merge into my lane right in front of me and then slam on your brakes? In that case, you made it impossible for me to maintain a safe distance.
This has been arbitrated in court (at least in my neck of the woods), if you merge and in doing so cause an accident you're a fault. The entire law system is setup to relate to the actions that a "reasonable" person would do. It isn't reasonable to expect the person who you've just merged in front of to immediately be at a safe distance (in fact you, the merger, are responsible for merging in a way that's safe.)