Only 1 lane in each direction open on I-40 bridge
Posted: Wednesday, September 8, 2010 8:01 pm
WEST MEMPHIS, Ark. (AP) — The Mississippi River has become an even more daunting geographic obstacle for thousands of drivers like Trent Hanks.
Beginning Tuesday, the Tennessee Department of Transportation closed all but one lane in each direction on the Hernando DeSoto Bridge carrying Interstate 40 traffic between Arkansas and Memphis. The closure is part of the agency’s decade-old effort to make the span earthquake-resistant. The lane reductions will last into November.
For Hanks, a 21-year-old electrician, it likely means a detour to the Memphis & Arkansas Bridge carrying I-55 traffic, downstream and south of the I-40 span, as he makes the daily commute from his West Memphis home to a job site in Bartlett. He figures traffic will be at a virtual standstill on the DeSoto span.
“It’s just going to be a nightmare,” he said.
The closures could cause major disruptions for both local and cross-country traffic. The 37-year-old DeSoto bridge last year accommodated nearly 46,000 vehicles daily.
Like Hanks, many motorists probably will veer south to take the 61-year-old Memphis & Arkansas Bridge, the only other local vehicular span over the Mississippi, said John Cameron, deputy city engineer for Memphis.
“There certainly will be some inconvenience to people who are traveling through town and are unaware,” he said.
Commonly called the “old bridge,” the Memphis & Arkansas span last year handled more than 48,000 vehicles a day. It is not slated to undergo seismic-retrofitting work.
If the DeSoto bridge work is inconvenient to cross-country drivers, it will be a major impediment for the commuters who must cross the river daily. Data from the 2000 Census showed that 10,185 Arkansas residents worked in Shelby County, Tenn., while more than 1,600 Shelby County residents worked in Arkansas.
Anticipating potential problems, TDOT has been meeting with emergency-response agencies on both sides of the river. The plan that emerged includes having a TDOT “HELP” truck assigned to the DeSoto bridge at all times, with additional trucks on hand during morning and afternoon rush hours.
Also, TDOT previously had installed a gate on the bridge that’s designed to give emergency vehicles quicker access to accident sites and deal with traffic problems.
To ease congestion on the Memphis & Arkansas bridge as it absorbs the additional traffic resulting from the DeSoto work, officials will close the ramp that carries westbound Crump Boulevard traffic onto I-55.
The lane closures come as a new phase begins in the long-term seismic-retrofitting project on the DeSoto bridge. Under way since 2000, the project is designed to ensure the span can withstand a quake of up to 7.7 in magnitude.
The retrofitting work has been completed on the portion of the bridge directly over the Mississippi, but construction continues on the approaches.
So far, the project has cost more than $175 million, with three years and another $75 million to go.
The long timetable for the project can be explained largely by the piecemeal nature of the work and an incremental funding process involving two states, said TDOT spokeswoman Julie A. Oaks.
“We’re partnering with Arkansas, so we both have to have funding at the same time,” she said.
The federal government is paying 80 percent of the costs, with two states splitting the remainder.
The phase of work that begins this week involves replacing a critical expansion joint along bridge piers near the Riverside Drive exit in Memphis. During a quake, the new joint will “open,” or move, up to 16 1/2 inches — more than twice the range of the current joint, said Fred Stephenson, resident engineer with the firm TRC Solutions, which is helping with the project.
“The only way we can get to that (joint) is to cut the deck,” Stephenson said.
With the new joint, and the ones already installed in the longer parts of the span over the river, the bridge will be able to better absorb the seismic forces from a quake on the New Madrid fault zone. Extending from the southern tip of Illinois to Marked Tree, Ark., only about 35 miles from downtown Memphis, the fault zone generated a series of massive temblors in late 1811 and early 1812.
Charles Langston, director of the Center for Earthquake Research and Information at the University of Memphis, said that in addition to being important to the nation’s economy, the DeSoto bridge would be vital during relief and recovery efforts following a major quake.
“It’s a really critical lifeline,” Langston said.
Information from: The Commercial Appeal, http://www.commercialappeal.com
Published in The Messenger 9.8.10