Two lanes of traffic will be left open in each direction during the four-year construction of a $126 million downtown freeway makeover, members of the Downtown Chamber of Commerce were told Thursday morning.
Jim Floyd and Julie Alcantara of the Volkert engineering firm that is providing construction engineering and inspection for the project and is overseeing construction also said the project will include "a monster wall" at the side of Cameron Hill.
They said that is necessary to help limit the expanse of the project that required the taking of only two businesses on Carter Street.
"For such a huge project it has a very limited footprint," Mr. Floyd said at a meeting at the Mountain City Club.
He said the project is "very, very similar" to the 1.6-mile, $106 million project that was just completed from Signal Mountain Boulevard to the Olgiati Bridge.
The new work will include adding a lane and new shoulder on each side of the bridge as well as taking out the current S Curve at Fourth Street. That will become a straight shot from the bridge south.
Mr. Floyd said the section of US 27 that starts at the split with I-24 was designed in the 1950s and 1960s for a 55 mph speed limit and to handle 15,000 to 20,000 vehicles per day. He said it now has about 70,000 vehicles a day.
Design on the project was started in 2006 and the right of way was purchased last year.
He said the narrow design with curves and minus shoulders does not meet current safety standards. He said an extreme re-design was necessary to make it meet the latest regulations.
He said the medians do not meet safety requirements and the entrance and exit ramps are very undersized.
Substantial pavement repairs will also take place.
He said it is unusual that a TDOT project takes four years - usually they are complete by at least three years.
On the 2.3 miles of the project, there will be 33 walls built and 10 bridges rebuilt.
Mr. Floyd said Dement Construction was the low bidder of two firms that sought the project. He said it is using Wright Brothers - the builder of the prior US 27 project - as a subcontractor since it has experience building the walls. "It's a great team," Mr. Floyd said.
He said the project will include a southbound collector road tying Fourth Street to Sixth Street and MLK Boulevard.
At Fourth Street, where the new wall that is taller than any built on the prior project will be, vehicles will descend some 30-40 feet when going off the freeway. He said another wall will be "holding up the freeway."
He said the connector road will give good access "for the Blue Cross folks.'
Ms. Alcantara said the project will be built in four phases. The first, which is already underway, is focused on the northbound side and will include construction of a new exit at Main Street that will come out at 13th Street near the Convention Center.
In the second phase, new bridges will be constructed and traffic will afterward be shifted to those while work moves to the soundbound side. Work starts on the monster wall, which will take two years to construct.
The Olgiati Bridge will be widened during the third phase and bridges will be constructed on the southbound side.
The final phase includes the new MLK Boulevard and Fourth Street ramps. There will be direct access from the Olgiati Bridge on the connector road all the way to MLK Boulevard. New lighting will be put into place and traffic cameras repositioned.
During the next six months, the city is getting traffic signals along Fourth Street updated so they will mesh with different phases of the construction and the final configuration.
Sharon Braden will be in charge of publicity and Lawson Whitaker will be the photographer for the project.
The project has its own website: