One of Chattanooga's biggest and costliest road projects is behind schedule.

The U.S. 27 expansion project won't be finished until January 2020, which is six months later than anticipated.

The road was built to hold half the number of cars that travel it each day.

A spokesperson for the Tennessee Department of Transportation said rebuilding it, without taking more land, has been a challenge.

Jason Jones has watched Chattanooga grow around his downtown restaurants, Moe's Original Bar-B-Que on Market Street and Mellow Mushroom on Broad Street.

He has also watched construction projects attempt to keep up with the traffic.

"Tourists get a little weirded out. But it will be better when it gets done," Jones said.

He said the Highway 27 project has slightly impacted business at Mellow Mushroom since it started in 2015.

It will be another year and a half before it's finished.

"I'm not surprised. That's just how those projects go. It's a big endeavor, it takes a lot of work," he added.

TDOT officials call the project one of its most complex.

That's because it includes nearly 40 retaining walls like the one under Blue Cross Blue Shield.

"You try to figure out what you're going to encounter. But when you actually get out there and begin the work, there's always a surprise or two on any project, especially one that large," TDOT Spokesperson Jennifer Flynn said.

Crews encountered 10 times the amount of rock they expected when they started moving dirt. That surprise set the project back six months.

"We encountered a lot of rock that ended up making a lot more work. And then also there were a lot more voids that they had to fill to stabilize the slope," Flynn added.

The project has come with lane changes and ramp changes.

TDOT altered ramp configurations last year when accident numbers spiked.

Numbers show those changes helped and drivers have become more aware of how to navigate the construction.

Before stop signs were added to the downtown on-ramps, there were 56 reported incidents.

That number was cut by more than half during the same time this year.

It's business as usual for Jones. He's not sweating the delay or traffic challenges for customers because he believes it will pay off in the long run.

"It's a little short-term pain for a long-term gain. I'm okay with that," he said.

Southbound drivers can expect a major traffic shift before the end of the year.

Crews said it will impact some of those stop ramps downtown.

Of course, Channel 3 will let you know when that happens.