UrthWurm 2002 Urthwurms move differently from earthworms; rather than burrowing through dirt, they seek existing tunnels and are stopped dead in their tracks if they run into an obstacle head - on. (old-games.com)
The MULTI can run both vertically and horizontally, so that it can thread its way through the mess of existing tunnels and shafts. (treehugger.com)
Amtrak has said that commuters could face a crisis without alternatives to the existing tunnel between New Jersey in Manhattan, which was damaged during Hurricane Sandy. (therealdeal.com)