Memphis

A container ship rammed into the Francis Scott Key Bridge in Baltimore around 1:30 a.m. on March 26, 2024, causing a portion of the bridge to collapse into Baltimore Harbor. Officials called the event a mass casualty and were searching for people in the waters of the busy port. This event occurred less than a year after a portion of Interstate 95 collapsed in north Philadelphia during a truck fire. That disaster was initially expected to snarl traffic for months, but a temporary six-lane roadway was constructed in 12 days to serve motorists while a permanent overpass was rebuilt. U.S. cities often face similar challenges when routine wear and tear, natural disasters or major accidents damage roads and bridges. Transportation engineer Lee D. Han explains how planners, transit agencies and city governments anticipate and manage these disruptions. How do agencies plan for disruptions like this? Planning is a central mission for state and metropolitan transportation agencies. T...

Rivers are critical corridors that connect cities and ecosystems alike. When drought develops, water levels fall, making river navigation harder and more expensive. In 2022, water levels in some of the world’s largest rivers, including the Rhine in Europe and the Yangtze in China, fell to historically low levels. The Mississippi River fell so low in Memphis, Tennessee, in mid-October that barges were unable to float, requiring dredging and special water releases from upstream reservoirs to keep channels navigable. Conditions on the lower Mississippi may be easing somewhat, thanks to early winter rains. But as Earth scientists at the University of Memphis, we see this year’s dramatic plunge in water levels as a preview of a climate-altered future. River barges are an efficient way to transport bulk commodities, such as grain shipments, and heavy equipment over long distances. But that’s true only for normal water conditions. Increased swings between extreme low...