Study Projects Lowest Tolls in the State for I-25 South Gap Express Lanes

Aug. 15, 2018 - Express Lane Choices Will Offer Free Carpool, Motorcycle and Toll Rates Likely to be Lowest in Colorado

DENVER—Tolls are expected to be the lowest in the state once Express Lanes are in operation on the I-25 South Gap project, according to a traffic and revenue study released today by Colorado's High-Performance Transportation Enterprise (HPTE).

The study includes a survey of motorists who travel the I-25 South Gap corridor, which links Colorado Springs and Denver. Motorists were asked about what they would be willing to pay for a reliable trip on the Express Lanes after they are built on the 18-mile section between Monument and Castle Rock. Based on the results and other data, the study found a rate of $0.15 per mile, or around $2.25 per trip (2017 dollars), would likely provide for a reliable travel option while improving travel times across the general-purpose lanes. This would be the lowest per-mile rate in Colorado.

Toll revenues will pay for the tolling equipment and installation, tolling operations and maintenance of the Express Lanes in the I-25 South Gap corridor to include snow plowing, and debris removal and pavement repairs.

"We conducted a thorough and objective study to determine what is the value of time for motorists who travel the I-25 South Gap corridor," said HPTE Director David Spector. "We found the majority of those surveyed support a travel option that reduces congestion and provides a reliable, shorter travel time in exchange for paying a toll."

The study will be used as a key source of information for the HPTE Board when it makes a final decision on toll rates a few months before the Express Lanes open to traffic, expected in 2022. At that time, HPTE will conduct additional public outreach before setting toll rates.

"Douglas and El Paso counties are forecasted to experience a 48 percent increase in population from 2015 to 2040, and traffic will increase as a result," Spector said. "Express Lanes are a critical mobility solution that provide businesses, commuters and all travelers the option of a reliable, shorter travel time now and into the future."

Construction will begin on the northern section of the I-25 South Gap project in early September. The project will widen the highway between Monument and Castle Rock from two to three lanes in each direction, widen shoulders, rebuild bridges, build new wildlife crossings and make technology improvements.

The project's new lane will be an Express Lane; drivers will have the choice to take this lane for a shorter travel time in exchange for paying a toll, or can choose to use the general-purpose lanes for free. High-occupancy vehicles (HOV) or carpoolers with three or more people in a vehicle, and motorcyclists will be able to use the Express Lanes for free. Drivers will need an ExpressToll account and pass to pay a reduced rate, and other drivers can choose to pay using License Plate Toll, which is the toll plus charges to mail the bill.

ExpressToll passes work on all CDOT Express Lanes, the Northwest Parkway and E-470.

Colorado has Express Lanes on US 36 between Boulder and Denver; on I-25 in downtown Denver and north of Denver; and on eastbound I-70 in the mountain corridor, between Idaho Springs and Empire. In the next few years, Express Lanes will open on C-470 between Wadsworth and I-25; I-25 North between Johnstown and Fort Collins; I-25 North between 120th Avenue and the Northwest Parkway/E-470; and on I-70 between Brighton Boulevard and Chambers Road.

About the High Performance Transportation Enterprise (HPTE)
The HPTE is a government-owned, independent business within CDOT. It searches out innovative ways to finance projects to help Colorado fulfill its commitment to increase travel choices through options that include Express Lanes, transit, biking, walking and carpooling. For more information, visit

About Express Lanes
Express Lanes increase roadway capacity and help manage congestion on the highways. The use of toll pricing during peak travel times reduces delays, manages congestion and maintains reliable travel times. Express Lanes are currently open on I-25 between downtown Denver and 120th Avenue, US 36 between Denver and Boulder, and on I-70 between Idaho Springs and Empire. For more information, visit