1. A disparaging term used to describe a person or a group of people typified as lazy or lacking style and traveling on the freeway, usually by motorcycle.
2. Any card, or collection of cards, in a cardgame hand that is neither very high nor very low but rather middling and thus undesirable.
3. Any lousy card or resource in a cardgame or boardgame.
"Hold on, an exit is coming up here. Let me pass this roadtrash real quick and we'll stop at the gas station."
"Did you hear about Andy playing hearts the other day? He picked up his three cards and threw 'em across the table! Man, I couldn't believe the roadtrash that Alex had passed him!"