Drivers can expect about another year of construction on C-470 between I-25 and Wadsworth Boulevard as crews enter the home stretch of a project to add toll lanes intended to reduce congestion on the corridor.

The C-470 Express Lanes project will add two express lanes — which will be tolled — westbound from I-25 to Colorado Boulevard, narrowing to one from Colorado Boulevard to Wadsworth Boulevard. One express lane will be added to the eastbound stretch from just west of the South Platte River to I-25. The project will also see bridges and overpasses widened, curves realigned, and a host of other tweaks to the corridor, according to materials published by the Colorado Department of Transportation, or CDOT.

The project is expected to save motorists upwards of 18 minutes of travel time on the roughly 12-mile stretch between I-25 and Wadsworth Boulevard during rush hour. Tolls will vary depending on traffic flow, and would range up to $6 to travel the entire express-lane corridor during peak hours.

The project is moving along a steady pace and is on schedule, said Stacia Sellers, a communications manager with CDOT.

“We're making great headway,” Sellers said. “We should be completing the last bridge widening this month, at Yosemite. Willow Creek Trail will be closed for a few weeks as we make improvements like trail widening and drainage work.”

Sellers said the express lanes will be the innermost lanes of the highway, so crews are currently progressing on adding outside lanes to the highway that will become general purpose lanes. At its widest, the highway will go from its current four lanes to seven.

The new lanes are about three-quarters finished, Sellers said, and traffic will be shifted onto them as they're completed to allow crews to work on the express lanes.

Crews are about halfway finished building noise walls that will line about three miles, or roughly a quarter of the project length, Sellers said. Noise wall locations were determined by consultation with surrounding neighborhoods.

Roughly 100,000 drivers use the segment of highway every day, according to CDOT, with volumes projected to increase 40 percent by 2035.

“This project will help tremendously with congestion,” Sellers said. “More people are moving in all the time, and more homes and businesses are lining that corridor. Once the express lanes are open, people can choose if they want that trip time reliability.”

The project seems to be going smoothly, said Roger Partridge, a Douglas County commissioner who was an instrumental part of the coalition of municipalities and counties that pushed for the project.

“I hear from the travelling public that people are mostly surprised by how well the project and traffic are moving,” Partridge said.

Douglas County ponied up $10 million of the project's $276 million cost. An additional $110.6 million came from state and federal funding, with the balance coming from loans that will be paid off with toll revenue.

The decision to make the new lanes tolled was the result of resident surveys, Partridge said.

“We did phone polls that asked if people thought the project was necessary, and the answer was overwhelmingly yes,” Partridge said. “The funding just wasn't there to make all the new lanes general purpose, so we asked people if they wanted to see a new sales tax, gas tax, or toll lanes, and toll lanes won.”

Partridge said the goal is to use variable tolls to ensure that traffic on the express lanes is always moving at 45 mph or faster.