New Memphis Bridge Aims for Unshakable Strength

A map showing earthquakes in the New Madrid Seismic Zone since 1970. The map was published in a draft environmental assessment for the new Interstate 55 bridge project. (Tennessee Department of Transportation)

Arkansas Department of Transportation Director Jared Wiley is settling in since taking over ARDOT”s top job in January, and one of his biggest jobs ahead will be following progress on a new interstate bridge at Memphis.

An engineer by training, Wiley sat down with Keli Wylie, his assistant chief engineer for program delivery, to discuss the forthcoming Interstate 55 bridge over the Mississippi. Replacing the existing 75-year-old bridge is such a priority that Arkansas and Tennessee have pledged up to $250 million each to build it. The federal government is putting up $400 million.

“The West Memphis-Memphis corridor is a heavily traveled freight corridor, maybe the heaviest in the nation,” Wylie said. “We expect to see it continue to grow.”

One worry is that the current bridge wouldn’t survive a strong earthquake. The crossing is in the New Madrid Seismic Zone, near the fault that triggered massive earthquakes in 1811-1812, long before any bridges crossed the Mississippi. No comparable quakes followed, but scientists say the potential for a “big one” persists.

“Of course, this bridge will be built to withstand a seismic event, which is important because we’re building on a major fault line,” Wiley said. “And folks have been predicting for years that it’s going to happen again, and we’ve just been blessed that it hasn’t. This new bridge will be built to the latest seismic standards.”