In 2019, the Colorado Department of Transportation (CDOT) began the I-70 Westbound Mountain Express Lane project. With the project nearly wrapped, those involved view it as a success.

To get to the Rocky Mountains, Denver metro residents turn to I-70. The interstate experiences huge spikes in traffic on the weekend as people travel to and from the area.

To alleviate the congestion, CDOT added an Express Lane, also known as a Peak-Period Shoulder Lane (PPSL), which extends for 12 miles between the Veterans Memorial Tunnels and Empire Junction. Although this is not the entire length of I-70, the lane has led to less congestion during peak travel times. This project focused on the westbound side of I-70. The department previously installed an Eastbound Mountain Express Lane on this stretch of I-70 in 2015. CDOT has plans to work on other parts of I-70 in the future.

The most feasible way to add the tolled Express Lane was to widen the shoulder and convert it into a lane. “The Federal Highway Association (FHWA) granted us the right to use the shoulder because it’s an interim operational improvement,” says Jeff Hampton, a Project Engineer with CDOT.

The lane is only available during peak times – the weekend and holidays. “As per CDOT’s agreement with FHWA, the lane is only allowed to be in operation part-time and for a limited number of days per year,” Hampton says. In addition, CDOT aims to develop a permanent solution with the stakeholders within the next two decades.

With no shoulder available when the PPSL is operational, CDOT needed to develop a plan of action for when accidents and emergencies occur.

CDOT has an extensive communication network throughout the area, including many cameras to monitor the highway. “We also have a courtesy patrol on contract to work during peak times that is ready to respond to cars that need towing,” Hampton says. "If there’s an emergency, we can shut the lane down as there are emergency pullouts for drivers to pull off the PPSL if the situation requires.” There are also multiple egress points for vehicles to exit the lane.

Although Hampton feels the project has met its goals, there were challenges to overcome. The biggest one was how to build the PPSL while keeping traffic flowing. Hampton credits the locals for buying into the project for overcoming this challenge.

The pandemic and the reaction threw a monkey wrench into the timing of the project. During the first few months of the shutdown, traffic counts were significantly lower. By the summer of 2020, traffic counts shot back up and eventually surpassed earlier levels. “The lower traffic counts at the beginning of the project were a good opportunity to move the project forward,” says DOT Spokesperson Presley Fowler, “but quickly became a challenge as more motorists used I-70.”

The pandemic also impacted this project – like many others – in terms of personnel. Staff missed days, and decisions had to be made on how to cover for them while keeping the project moving.

The narrow corridor was another challenge the construction team faced. There were also two rockslides while the project was in full swing.

Graham Contracting served as the prime for the project. Hampton expects to see them more in the future. “After nearly three years of working together, I’ve seen Graham worked hard, worked with us, has a good staff and kept plugging along through every challenge.”

The project was financed through a Federal INFRA grant and had a budget of $66 million. However, Hampton expects it to wrap a few million below. He credits budget management, good oversight of day-to-day items, and the entire project team for keeping track of the budget. The project included funds for Minor Contract Revision, and the team was well within those funds.

“The schedule was the biggest challenge,” Hampton says. “The project was eight months behind schedule as there were challenges with existing utilities.”

At this point, the I-70 Westbound Mountain Express Lane is open to the public. However, CDOT is waiving the tolls at this point as they are in a testing phase. According to Hampton, “We need cars in the lane to test equipment and ensure it works properly. We expect tolls to begin at the end of May.”

There have been some challenges with software, as the newer equipment on the westbound has had to integrate with the older software that was installed on the eastbound side. A third-party is serving as the tolling integrator working on installation of the new tolling equipment and working with the Colorado Transportation Investment Office to test the equipment before tolling begins.

Vehicles can pay the fee via their Express Toll Pass or the cameras will read the license plate and bill the driver. This will incur a higher rate.

With the project essentially complete and the I-70 Westbound Mountain Express Lane open for testing since July 2021, CDOT has been monitoring the public’s response.

“The public reaction has been super positive,” Hampton says. “Our stakeholders were very happy with how the project went and are happy to see us gone.” He credits the public response partially to keeping the public well informed.

Most importantly, CDOT has cut down the travel time in the corridor. They also have positive relationships with the locals and stakeholders in the area. “This project has helped us build positive momentum for future projects in the corridor,” Hampton says.