Widening part of U.S. 27 through downtown Chattanooga moves to forefront

The widening of a major highway artery — designed to reduce rush-hour commutes to the central city — hit a delay as another downtown Chattanooga road project was greenlighted.

The addition of more lanes to a 1.6-mile stretch of U.S. Highway 27 from Olgiati Bridge north to Signal Mountain Road is on hold as state road builders and environmental officials grapple with pyrite, a mineral that causes acid runoff.

“We don’t know what’s going to happen on this project, but it is not going to happen anytime soon,” said Tennessee Department of Transportation spokeswoman Jennifer Flynn.

The road widening and ramp improvements were slated for 2009.

Meanwhile, work on U.S. 27 south of the bridge to Interstate 24 appears on track. The Tennessee Department of Transportation included right-of-way property appraisal and acquisition for 2010 on the 1.5-mile section of the highway, which carries about 69,000 commuters daily.

The improvements to U.S. 27 south of the Olgiati, along with adding lanes to the bridge itself, possibly will leapfrog the work north of the river, where road builders have uncovered pyrite. TDOT is working with the Tennessee Department of Environment and Conservation on a remediation strategy, Ms. Flynn said.

Pyrite is an acid-forming mineral, TDEC spokeswoman Tisha Calabrese-Benton said. When unearthed, pyrite will produce a weak sulfuric acid when water falls on it, she said.

“This runoff has the potential to affect both the color and the pH levels of any streams or other bodies of water,” Ms. Calabrese-Benton said.

Now, state road officials must figure out what to do with the pyrite before determining how and when to move ahead north of the bridge. TDEC and TDOT intend to encapsulate the pyrite properly — whether on site or at a special landfill, she said.

In 2005, when TDOT was remaking the Signal Mountain Road-U.S. 27 intersection, the mineral was found on a hillside where an entrance ramp was expanded. Workers had to cover the hillside, which boosted the cost of the ramp work by more than $400,000.

Work to replace the broken-down steel beam median barrier with a concrete barrier on Highway 27 north of the bridge should be completed by Aug. 31, Ms. Flynn said.

Steve Arnsdorff, developer of the new Two North Shore shopping center on the North Shore, said he’s glad the city did not wait for Manufacturers Road to be widened at the same time as U.S. 27 north of the bridge.

“We’re very grateful for the city’s foresight,” he said about the Manufacturers Road widening completed late last year.

SOUTH OF BRIDGE

Property appraisals and acquisitions for reworking U.S. 27 through the heart of downtown could take as long as a year, Ms. Flynn said.

A right-of-way field review likely will be done next year to assess what tracts may be needed for the project. However, officials have said the design basically remains within much of the existing right of way, so nearby buildings aren’t affected.

Since right-of-way acquisition is on TDOT’s schedule for 2010, actual work could start relatively soon thereafter. The project depends on funding, the TDOT spokeswoman said.

Steve Leach, the city’s public works administrator, said he is ready to see TDOT proceed.

“We’d certainly encourage them to move forward,” he said. “We always want things sooner than later.”

John Zeiser, president of Southern Champion Trey off Manufacturers Road, said there’s an issue of congested morning traffic flow on U.S. 27 going toward Interstate 24.

“As long as whatever they do allows for more open flow to get to main thoroughfares, that’s a good thing as far as we’re concerned,” he said.

DESIGN FOR YEARS OLD

TDOT is proceeding under the basic design for improving U.S. 27 south of the bridge that was crafted about four years ago.

Officials said a two-lane frontage road would be built on U.S. 27’s west side — the Cameron Hill side — starting at Olgiati Bridge and running to M.L. King Boulevard.

Intersections on the frontage road would be created at Fourth and Sixth streets and M.L. King to enhance connections with downtown and the Westside community.

ROUNDABOUT IN DOUBT

The early plan called for the frontage road to lead to a large roundabout at M.L. King that would replace the existing two big loops now leading on and off U.S. 27. However, planners are re-evaluating the roundabout.

“It’s not known for certain if there will be a roundabout included in this project because it may not function as required,” Ms. Flynn said.

In addition, the plan straightens some of U.S. 27’s “S” curves at the approach to the bridge, and longer ramps with more visibility will aid entries and exits from the road.

Adding lanes to Olgiati Bridge could be included in this project or be standalone work, Ms. Flynn said. The bridge must be widened before or along with the road expansion on the south end or the lanes won’t line up.

Planners also are reconsidering the closure of the southbound on-ramp connecting 12th Street to the highway after Westside residents objected, she said.

Cost estimates aren’t available on the projects. Work on U.S. 27 south of the bridge four years ago was estimated at between $20 million and $25 million.