1) Losing ones mind in a fit of justifiable anger.
2) State of mind leading to probable disproportionate violent response to causal situation.
Typified by bug eyes, flailing arms, stomping feet and ridiculous primal screams. 5 year-olds often go Road House when told to eat their vegetables or they'll get no dessert.
From the Movie Road House, especially the end which culminates with Dalton ripping out the throat of one henchman and murdering the rest while hunting down Wesley.
Bill showed up just in time for the meter maid guy to laugh in his face after writing a parking ticket. Bill promptly went all Road House.
Bishopsumo went all Road House when some dipshit Urban Dictionary editor rejected his definition.