Today is the day the Missouri Department of Transportation makes some major traffic-pattern changes on the Whitton Expressway between Monroe Street and Clark Avenue.
"We feel like things are going extremely well, on schedule," Patricia Lemongelli, MoDOT's Central District construction and materials engineer, told reporters Wednesday afternoon. "We're at a point where we feel like we've reached a major milestone - what I would call the last leg, the last stretch of the project."
By 3 p.m. today, officials intend to shift the eastbound traffic on U.S. 50/63 to the rebuilt eastbound bridge over Lafayette Street.
By the end of the day Friday, westbound traffic will be re-routed onto the westbound overpass. The westbound ramps to and from Lafayette Street will be closed.
Lafayette Street through the interchange area will remain closed so it can be rebuilt.
The contract with Emory Sapp and Sons does not specify Lafayette must be open before school resumes in August.
"We'll just have to see how the contractor's schedule goes," Lemongelli said.
Also Friday, the westbound ramp from Clark Avenue to the expressway - which has been closed since last year - will re-open to traffic.
Why not make both lane changes on the same day?
"I think a lot of people don't realize all the work that has to take place," Lemongelli said. "You have pavement markings that have to be changed, that don't match what will be needed and aren't where they need to be.
"We do one area at a time."
The $20.3 million project's main focus is creating an interchange between Whitton Expressway and Lafayette Street.
But it also involved widening parts of the 1-mile stretch between Monroe Street and Clark Avenue, and that required demolishing then replacing the Chestnut Street and Jackson Street overpasses.
Chestnut was finished last year.
Once the traffic pattern is shifted this week, Lemongelli said, work will begin on the new Jackson Street overpass, which was removed more than a year ago.
It's supposed to be finished and open to traffic by mid-September.
The shift to the main driving lanes also doesn't mean an immediate change in the lower, 35 mph speed limit through the construction zone, Lemongelli said.
"We do have some work that still needs to take place," she explained. "We always encourage our drivers to maneuver through work zones safely," she said.
Once the construction is finished, the expressway traffic pattern will return to the pre-construction, step-down speed limits of 65 mph east of Clark Avenue, dropping to 50 and then to 40 mph approaching the Monroe Street traffic signals.
Also, Lemongelli pointed out, the new interchange is at a lower grade than the previous highway, improving visibility in the westbound lanes for traffic approaching Monroe Street.
Sound-barrier walls still need to be erected along portions of the expressway.
"The panels are going to start going up toward the end of June and in July and into August," she said.
The entire project is scheduled to be finished near the end of October, Lemongelli said, adding "if things continue to go well, we might even be able to beat that schedule."
Separate from the Lafayette Interchange project, she said, at some point later this year or in 2017, Clark Avenue will be closed over the highway so MoDOT can rehabilitate that overpass.