Definitions by Mista Scribbler

tunnel runner 

An individual who runs through a city’s transit tunnels with the intent of exploration, tagging or escape while dodging security patrols and trains.

"The police have been arresting any tunnel runners they catch trespassing in the subway system."

"Fucking pigs chased me while i was doing a tunnel run last night."

tunnel runner by Mista Scribbler June 6, 2003