City staff plans to introduce a bill to the Jefferson City Council today to move forward with placing a roundabout at the intersection of Clark Avenue and Dunklin Street.
The council will review a $152,556 contract with Bartlett & West to design the roundabout during its meeting.
"It's a much-needed improvement. It's a quirky, odd intersection," Ward 3 Councilman Ken Hussey told the Jefferson City Public Works and Planning Committee on Thursday.
Construction of the roundabout is estimated to cost about $1.7 million, City Engineer David Bange said.
Jefferson City and Cole County would partner on the project, Bange said, use funding from the half-cent capital improvement sales tax.
The Cole County Commission agreed with Jefferson City officials in January to pursue a roundabout for the Clark Avenue and Dunklin Street intersection.
Construction would not begin until 2022, Bange said.
If Jefferson City builds the roundabout, he said, the city would have to acquire a nearby building that currently houses the Joshua House Church at 1136 E. Dunklin St. A nearby gas station and some residences could also be impacted, he added.
In January, the Public Works and Planning Committee approved city staff's request to direct Bartlett & West to design a roundabout for the intersection following a traffic study of the area.
The City Council approved a contract with Bartlett & West in November 2017 to conduct a traffic study on the Clark Avenue interchange and corridor, from East McCarty to Hillcrest streets.
While the intersection is "functioning from a traffic capacity standpoint," Bartlett & West Project Manager Todd Kempker stated in a letter to Bange, the intersection can create confusion among drivers — primarily due to the left-turn bypass lane for traffic traveling east on Dunklin Street.
Bartlett & West considered a signalized intersection, as that would fix sight distance issues at the intersection; however, the traffic volumes at the intersection are below what is normally recommended for a signalized intersection, according to the traffic study. A signalized intersection could also lead to more vehicle crashes, Bange said.
"The volume isn't there to really justify a signal," he said. "Because of the introduction of these crashes that would happen (with a signal), it made sense that a roundabout would be a better option there, particularly in low-volume times. You wouldn't want to set up a situation where you were constantly stopping at a red light where there was no one at the intersection."
The initial cost to place a roundabout at the intersection — about $1.7 million — is higher compared to the initial cost to place a signal there — about $1.3 million — Jefferson City Public Works Director Matt Morasch previously said.
However, a signal would cost nearly $3.8 million over a 20-year period compared to a roundabout, which would cost a little more than $1 million, Morasch previously said. The large difference is due to the loss in service and daily costs, as well as replacement of signal equipment, he said.
Other future roundabouts potentially on the horizon for Jefferson City include three along Edgewood Drive — at Stadium Boulevard, Creek Trail Drive and Stoneridge Parkway — Bange said.