I’m sure you have heard the definition of insanity: doing the same thing over and over again and expecting different results.
Insanity…meet the 11 foot, 8 inch bridge in Durham, NC, where about once a month, a truck or RV driver thinks he can fit under the bridge, with disastrous results:
As the story goes, the railroad wanted to protect the train trestle from over-height trucks, so it installed a large beam at 11 feet, 8 inches, just low enough to decapitate trucks on a regular basis.
What are the safety lessons from this? Other than the obvious (make sure you know the height of your truck before you drive it) I think there are two things:
- Management of change – When you address one hazard, you need to consider the impact on other hazards. In this case, the railroad wanted to control a top-event hazard, bridge hits that could derail a train. But, in controlling that hazard, it created another hazard, repeated vehicle accidents that extend over a long period of time. This happens in other industries as well. Two years ago, OSHA pushed oil and gas companies to make sure workers wore their flame retardant clothing so that it covered their bodies, but that came during the hottest summer in many years. Heat-related injuries and deaths skyrocketed.
- When do we address hazards? – The lesson of what is sometimes called Szymberski’s Design For Safety model, the earlier you address safety, the more impact you can have on it. If we could turn back the clock and design a higher bridge, these accidents wouldn’t happen and we would eliminate the hazard to trains. However, by waiting until the accidents are already happening, the only tools are administrative – a few low clearance signs and a 25 mph speed limit, apparently.