I-25: Monument to Castle Rock
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The I-25 “South Gap” is an 18-mile stretch of I-25 from Monument to south of Castle Rock, connecting Colorado’s two largest cities, Denver and Colorado Springs.
How to Use Express Lanes
I travel in a:
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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.
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HOV3+ users must have an ExpressToll account, a Switchable HOV transponder set to “HOV” mode, and three or more people in the vehicle to use the Express Lanes for free.
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Motorcyclists can use the Express Lanes for free without a pass.
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Bus and other transit can travel in the Express Lanes.
Corridor Basics
- Lanes are open 24/7.
- 18 miles of Express Lanes from Monument to Castle Rock.
- HOV 3+ will be available with a switchable HOV transponder.
- Adjustable toll pricing system will be used – prices will depend on the time of day.
- Overhead signs will indicate current toll prices. Tolls will be collected through the vehicle’s ExpressToll account or a License Plate Toll.
- The Safety and Toll Enforcement Program is in effect. Sophisticated roadside technology is used to enforce the following rule:
- No weaving across double solid white lines.