I-25 South Gap: Monument to Castle Rock

This project will build one new Express Lane in each direction of I-25 along an 18-mile stretch known as "The Gap"—south of Castle Rock to Monument. The I-25 South Gap Express Lanes opened with tolls waived for testing in December 2021.
How to Use Express Lanes
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Vehicles with one to two people pay a toll to use the Express Lanes with an ExpressToll account or through a License Plate Toll.

Vehicles with three or more people must have an ExpressToll account and Switchable HOV transponder to use the lanes for free.

Motorcyclists can use the Express Lanes for free without a pass.

Bus and other transit can travel in the Express Lanes.
Corridor Basics
- 18 miles from Monument to Castle Rock
- The project will add one Express Lane in each direction, along with safety, infrastructure, and wildlife crossing improvements.
- Motorists will have a choice to take the general-purpose lanes for free, or drive the Express Lanes for a shorter and more reliable travel time in exchange for a toll.
- Vehicles with three or more people and motorcycles will be able to use the Express Lanes for free.
- Substantial construction completion is scheduled for late 2021, with tolling to begin in 2022.
- Overhead signage will indicate toll prices, and tolls will be collected through ExpressToll account or through License Plate Toll.