Their tractor-trailers make good road blocks, and drivers have been known to deploy them to help police officers capture criminals on the run.
I came upon this example on TruTV, one of those cable-channel "action video" shows that are as entertaining as anything, at least for a while. A short segment shot by a state trooper's dash camera showed a pair of rigs blocking a small pickup whose driver was fleeing for some reason or other.
He tries to pass one rig on the right, but the trucker pulls over more and squeezes the fella's pickup against the guard rail. Now stopped, the fella
hops out the passenger window and down the embankment. Troopers chase him on foot and soon collar him, then walk him back up the slope.
I stop-framed the video to get these pics. The video doesn't show everything, but enough to suggest that the truckers deserved medals for helping the troopers in the southeastern state. The good guys didn't hang around, though. The narrator said they just continued up the road, unidentified but not unappreciated.