The railroad underpass on Main and Wood St. in Concord traps or decapitates about one truck every three months.  My morning commute was delayed by this wedged truck. As encounters with this bridge go, this one was relatively benign.  I suspect that deflation of the tires will be all that is required for a smooth extrication.  It is not uncommon to have the entire roof line sheared off. Such was the recent experience of a volunteer driver for Open Table who was transporting donated food items in a rental truck.  What amazes me is that no one has thought to install a height gauge of the type you find when entering a parking garage.