Stop us if you've heard this one before: Construction on C-470 is nearly finished.

The years-long C-470 Express Lanes Project, which will add tolled lanes along the busy highway, is scheduled to be completed this summer, according to the Colorado Department of Transportation, or CDOT.

That's about a year after the original expected completion date, and four years after the project began in 2016. CDOT placed the project's contractor, a joint venture of Flatiron Construction and AECOM, in default last summer after repeated delays and what CDOT called misleading updates.

“CDOT's priority is getting this completed as quickly and safely as possible so we can bring it to the traveling public,” said Tamara Rollison, a spokeswoman for CDOT. “You've probably noticed whenever you're out there, there's work taking place, including weekend and night closures.”

Once completed, the project will add at least one, and in some places two toll lanes to each direction of the heavily congested corridor between I-25 and Wadsworth Boulevard. Motorists could save up to 18 minutes if traveling the full 12-mile length of the lanes, according to CDOT estimates.

Tolls could range as high as $6.60 for a full-length westbound trip during afternoon rush hour, according to CDOT documents. The high end for eastbound travel could be $4.85 during morning rush hour. Tolls will be lower in off-peak times and for motorists only traveling partway. The goal is to keep traffic moving at least 45 mph at all times.

The toll lanes are expected to be complete sometime in the spring, Rollison said, and motorists will be able to use them for free for a few months while crews finalize installation and testing of tolling equipment.

Tolls will be assessed much like they are on E-470 east of I-25, Rollison said, utilizing license plate readers that will send a bill to the driver's home. Drivers can also buy electronic passes that are good on all the state's toll roads.

The remaining work is primarily paving, lane striping and signage installation, Rollison said.

In the meantime, CDOT is levying fines of $51,000 a day against Flatiron and AECOM for the behind-schedule work, Rollison said.

“We like these projects finished within a certain time frame,” Rollison said. “We've been exercising our recourse as laid out in our contract with them.”

The project's total cost is still in the neighborhood of $276 million, Rollison said. About $10 million of that is from Douglas County, and an additional $110 million came from state and federal funding.

Flatiron and AECOM are “working to safely expeditiously complete the project,” said Michael Swenson, a spokesman for Flatiron.

“We've been working with CDOT on this all the way through,” Swenson said. “We've focused significant resources on the project.”

Swenson declined to answer if the contractors have worked to change or improve their methods since being placed in default.

The project's completion will bring welcome additional capacity to the local transportation grid, said Keith Reester, Littleton's director of public works.

Still, Reester said, "you can't build your way out of congestion."

"You can, however, add capacity while you look at longer-term solutions: mode changes, shorter trips, working to help people live closer to their jobs and things like that," Reester said. "You're not going to get thousands of people to decide to stop driving tomorrow."