Ships hit bridges much more often than people realize, and while most of the outcomes are minor, such events can present big risks to bridge users, ship operators, and infrastructure. Bridge design standards that address such risks are issued and updated periodically by the American Association of State Highway and Transportation Officials, but they do not mandate adding protection to existing bridges. Yet the size of ocean-going cargo has grown substantially in the past 30 years, amplifying the risks for bridges over ocean-connected waterways.

To understand just how safe our major U.S. bridges are today, we talk with Mike Winters, P.E., who is Senior Structural Engineer with Moffatt & Nichol, a U.S.-based global infrastructure advisor. Mike is the principal U.S. representative to an international committee established by the Permanent International Association of Navigation Congresses to develop guidelines associated with ship collisions with bridges and other fixed structures.