The act of taking a shit on the side of the highway when there is no bathroom availible.
Gary had a serious case of turtle head poking while traveling down I-696 near Detroit. With no shitters in sight, he pulled over and took a Highway Dump in front of his car. He used his pants and underwear to wipe his ass, and was on his way.
by Floss 69 January 21, 2006
Get the Highway Dump mug.