The free ride on the new Interstate 25 express lane north of Denver is almost over. Starting April 7, drivers who use the new third lane between Berthoud and Fort Collins will have to pay to be there, ending a months-long test period that let commuters try the lanes without paying tolls.
According to tolls, which will launch on April 7, the roughly 14-mile stretch that spans mile markers 250 through 269 will begin charging in both the northbound and southbound directions, as per Kygo. Prices will shift based on traffic and time of day and will be shown on overhead signs. Drivers can pay through an ExpressToll account and transponder or through a license-plate toll, while vehicles carrying three or more people and using a switchable HOV transponder will be exempt from tolls.
Where the lanes stand now
CDOT’s I‑25: Berthoud to Fort Collins page notes that the corridor, which runs about 14 miles, opened in December 2023 with tolls temporarily waived for testing. The express lanes are built for adjustable pricing intended to keep traffic flowing, not just to collect fees. The project page also breaks down who can use the lanes for free and explains that overhead signs will show the toll that applies when a driver enters.
Why are tolls coming
The tolls are built into the financing and operations plan for the broader I‑25 North expansion, which received a major TIFIA loan from the U.S. Department of Transportation to help pay for construction. Planning documents and recent coverage describe Colorado shifting toward more dynamic, real-time pricing on express-lane corridors in 2026, using tolls as a traffic-management tool designed to preserve predictable travel times.
How tolling will work and how to pay
Most drivers will be billed automatically. Those with an ExpressToll account will have tolls charged through a transponder, and those without a pass will receive a license-plate toll. CDOT’s Get a Pass guidance explains that switchable transponders let drivers flip into HOV mode for free trips when they have three or more occupants, and that sticker passes and accounts typically lower the per-trip toll compared with being billed by license plate.
What drivers should watch for
Before entering the lane, drivers are advised to check the overhead price boards. The amount shown is what a transponder holder will pay for that specific trip. Motorists are instructed to enter and exit only at the marked access points with dashed lines to avoid violations.
Local coverage has detailed repeated delays in launching tolls on the North I‑25 express lanes and has highlighted that enforcement programs on Colorado express lanes have issued civil penalties for rule violations. That history suggests that drivers can expect billing details and enforcement reminders to roll out alongside the start of tolling…