A major overhaul of the intersection of West Lamar Alexander Parkway (U.S. Highway 321) and the U.S. Highway 129 Bypass in Maryville is set to begin Monday night.
The $4 million Tennessee Department of Transportation safety project will reconfigure turn lanes and ramps, eliminate permissive left turns (left turns without an arrow) and ease congestion with the widening of the bypass to six lanes from Mall Road to the parkway, in efforts to reduce the higher-than-average crash rates at the intersection.
When the city initially applied for the safety project in 2012, the intersection had a crash rate of 1.86 per million cars, which is more than double the state average of 0.91 crashes per million.
“What we need is to reduce the congestion at the intersection. That’s the biggest problem we have there, and causes most of the fender bender and minor accidents,” said Kevin Stoltenberg, Maryville city engineer. “Obviously, the left turn if you’re going westbound on 321 backs up really bad. ... What the safety project is going to do is provide dual left-turn lanes and they’ll be protected (arrow) only.”
The need for accident reduction at the intersection has resulted in full federal funding of the costly project through the Highway Safety Improvement Program.
The road project is to be completed in three phases, ending on or before July 31, 2019.
During Phase 1, crews will work on the northwest corner of the intersection. Traffic turning right onto 321 westbound will have a detour option at Foothills Mall Drive to avoid the construction area — the only anticipated detour for the whole project. This part of the project is expected to be complete at the end of January.
Phase 2 will include work on the center lanes of both roadways, which will require shifting traffic to the outside lanes in all directions. The center-lane work is expected to be finished in April.
In Phase 3, work will be done to the outer lanes and shoulders, shifting traffic to the center lanes.
According to TDOT, the contractor is limited to lane closures during the following times during the work week: 9 a.m. to 3 p.m. and 7 p.m. to 6 a.m. to keep the road open during peak traffic flows.
While all dates are subject to weather delays and the project will be put on a winter hiatus from mid-January to late February, the city is optimistic that APAC-Harrison contractors, who have completed work in Maryville before, will be able to meet the project deadline.
“While these estimates can be a little hopeful sometimes, there is no reason we know of that this project can’t be done by the end of July,” said Maryville Director of Engineering and Public Works Brian Boone. “A lot of the work on the front end is utility driven. ... There’s not a lot of paving or stuff that requires warm weather on the front end.”
Boone added that the project is just the beginning of more urban infrastructure in the area.
“The takeaway from that will be more concrete, curb and gutter,” Boone said. “You’re going to see more single-turn lanes turn into double-turn lanes, and you’re gonna see a span wire traffic signal turn into metal — it’s going to change from a very rural-looking intersection into a more urban-looking intersection.”
According to Boone, the city hopes to ultimately extend Foothills Mall Drive to the Maryville Commons shopping plaza and continue the widening of West Lamar Alexander Parkway to Broadway Avenue, bringing roads up to match the growth of the area.