Long- and short-term solutions to the degradation of U.S. Highway 127, which serves as the main route from Signal Mountain to Chattanooga, were the topics of discussion at a public meeting organized by the Tennessee Department of Transportation July 23.
Erin Woodson, project manager with local design and engineering consultancy firm Arcadis, said they're currently working through a technical study done on the 3-mile stretch of road that runs up Signal Mountain from Suck Creek Road to North Palisades Drive.
Over the past few years, deterioration of that portion of the road has resulted in rock slides, roadway failures and traffic delays, she told the crowd of about 50 who attended the meeting at Signal Mountain Middle/High School, including state Rep. Patsy Hazlewood.
Technical designs for the IMPROVE Act project on Highway 127, known locally as Signal Mountain Boulevard, began in August 2017 and are now complete. Once those are approved, Arcadis will move forward with drafting detailed designs.
This photograph taken in July from a Tennessee Department of Transportation drone shows damage from a rock slide on U.S. Highway 127 on Signal Mountain. Drones are becoming more commonly used in assessing damage and documenting project progress.Preliminary plans are expected in the summer of 2020, with right-of-way acquisition expected to begin that fall pending funding, she said.
Work on Highway 127 will not coincide with work planned for Roberts Mill Road, which is set to close Aug. 5-15 for road construction and utilities installation, according to the Hamilton County Highway Department. The work includes water line installation that is being paid for by a developer in the area.
The Highway 127 IMPROVE Act project includes the construction of three retaining walls on the road up the front of the mountain, as well as drainage, guardrail and proposed sight distance improvements. While not part of the IMPROVE Act project, rockfall mitigation will be conducted at the same time to minimize the impact on the public, Woodson said.
The budget for the IMPROVE Act project from construction to completion is between $16 million and $20 million, said TDOT Regional Director Joe Deering. The federal government will cover 80% and TDOT will match 20%.
Woodson said many of the culverts in the road's ditches are undersized according to current design standards, and those will be brought up to current standards to alleviate flooding issues.
Trees may be cleared away around the hairpin curve near Balmoral Drive to improve sight distance for drivers turning left onto 127.
Woodson said the rockfall mitigation will basically involve a mix of breaking off and pushing back loose, protruding or overhanging pieces; bolting rocks to the retaining wall; and layering the wall with shotcrete to prevent erosion. The same strategy was used in the slope stabilization projects TDOT did on the road last year, which have been successful, she added.
A slope repair and retaining wall project near "the spaceship house" is currently in the detailed-design phase and will be opened for bids this December. Due to greater than average rainfall in late 2018 and early 2019, worsening conditions forced TDOT to do emergency repairs at the site earlier this year. That particular retaining wall and slope repair were then separated from the IMPROVE Act project and fast-tracked, she said.
In response to a citizen's question about the right-of-way acquisition the project will require, Woodson said they have identified several areas that would require drainage easements, and the sight improvement work near Balmoral would also require permanent right-of-way.
Email Emily Crisman at ecrisman@timesfreepress.com.