More Cowbell

Truckers in Massachusetts keep hitting low overpasses. They need a warning, from cowbells.

The system was first installed in the 1980s when the state chained cowbells - no fancier than the kind used by farmers - to rubber flaps that said "Cars Only" and hung them from "Low Clearance" signs along the busy roads. Truckers who did not heed the warnings hit the flaps and heard the cowbells clang in enough time to stop before they rammed overpasses.

But years of neglect, punishing storms, and passing trucks have all but silenced the rustic warning system. These days, few cowbells remain, their rusted clappers dangling by the Longfellow Bridge and MIT, but most are long gone. Now, as the state prepares to replace a few of the missing rubber flaps, officials say they may redeploy the cowbells along the roads from the Museum of Science to the Boston University Bridge on Storrow Drive and to Magazine Beach on Memorial Drive.