When traffic on the I-40 and I-55 bridges reaches a standstill, it's typically due to construction work or an accident. But state transportation officials fear that traffic could bottleneck more often in the coming years without a third bridge over the Mississippi River.
Those fears are based on a new national report that predicts overall freight demand will double over the next 40 years, from 15 billion tons today to 30 billion tons by 2050. A third bridge over the river is one of hundreds of national solutions to improve freight delivery and dependability into the future.
"Where the bridge will be is still to be determined. That will be fully evaluated in the environmental process," says Joe Carpenter, chief of environment and planning at the Tennessee Department of Transportation (TDOT).
The Southern Gateway Project, as the new bridge study is called, is currently in the early stages of the environmental process. At the end of the month, TDOT officials will meet with the Memphis Metropolitan Planning Organization and the Arkansas and Mississippi Departments of Transportation to discuss possible locations. Currently, officials aren't sure if the bridge should connect Tennessee or Mississippi to Arkansas.
Unlike the I-40 or I-55 bridges, the new bridge will be built to modern seismic standards. Though some seismic retrofitting has been done on the I-40 bridge, TDOT spokesperson Julie Oaks says the I-55 bridge likely wouldn't withstand an earthquake.
"If one [of the supports] of the I-55 bridge fell, you'd have the potential that the whole bridge will fail," Oaks says. "With the older truss bridges, it's harder to go in and do any seismic retrofits."
The "Unlocking Freight" report, published by the American Association of State Highway and Transportation officials, also looked into other modes of transportation, such as rail and waterways.
"We have needs in waterways and rail for expansion so they can increase their cargo capability. That means we can lesson the load on our highway systems," Carpenter says.
Additionally, freight traffic in Tennessee will benefit from the expansion of the Panama Canal, which should be complete in about five years. That would bring more freight from Asia through this country's Gulf Coast ports.
"We need about 32,000 lane miles added to the interstate system and about 14,000 lane miles added to the national highway system, as well as additional lane miles at port facilities," Carpenter says. "The report tries to highlight how we're choking our own infrastructure and economic vitality."