When black people either walk slowly or stand around in high-traffic areas in large groups, blocking others from reaching their destination. Walking through a roadblack could cause verbal or physical attacks. It is best to avoid such attacks by avoiding roadblacks all together.
Tom, slow down! Don't blow through that roadblack!
WHAT DA HELL?!?!? WHAT CHO PROBLEM?!?!? (punch, slap, biff)