Express Lanes Safety Enforcement Program

What is an Express Lanes Safety Enforcement Program?

The Express Lanes Safety Enforcement Program is managed by the Colorado Transportation Investment Office (CTIO), the government-owned business within CDOT that oversees Colorado’s Express Lanes. The program encourages safe driving on CTIO’s network of Express Lanes by using sophisticated roadside technology to enforce Express Lane rules. Violators identified by this technology will be issued a civil penalty via mail based on the registered address of the vehicle’s license plate. Violations not paid within 20 days of issuance will increase to a $150 civil penalty.

Why was this program created?

The Express Lane rules are in place to keep all motorists safe and to keep traffic flowing along Colorado’s Express Lane corridors as efficiently as possible. Violators who ignore these rules present hazards to themselves and other roadway users. The safety enforcement program supports CDOT’s Moving Toward Zero Deaths initiative—eliminating all traffic fatalities and severe injuries on Colorado roads.

Violations Currently Being Enforced

While the Safety Enforcement Program will eventually apply to all Express Lane corridors, early enforcement will focus on the Express Lanes on the I-70 Mountain corridor, C-470, and I-25 north of Denver. Enforcement in the I-70 Mountain Corridor began on July 21, 2023, and civil penalties are currently in effect. The Mountain Express Lanes are peak period shoulder lanes that relieve congestion during peak periods, such as holidays and weekends. The rest of the time, they operate as typical shoulders to be used only by two-axle vehicles for emergencies and breakdowns.

Enforcement in the C-470 and I-25 north corridors began on Sept.1, 2023, with a month-long grace period. During the grace period, drivers received warnings in the mail when they were recorded committing a violation. Starting Oct. 1, 2023, drivers are issued a civil penalty for breaking the Express Lane rules.

Express Lane Rules:

  1. Drivers can only enter and exit the Express Lanes through a dashed line. Entering or exiting at any other point constitutes a failure to adhere to Express Lane rules and failure to pay a toll.  
  2. Drivers cannot use the I-70 Mountain Express Lanes outside of operating hours, except in an emergency or as an authorized emergency vehicle.
  3. Due to the narrow nature of the Mountain Express Lanes, no vehicle with more than two axles or exceeding 25 feet in length can travel in these Express Lanes at any time.

    Violations on the I-70 Mountain Express Lane include entering/exiting outside authorized access zones, unauthorized vehicles on I-70 Mountain Express Lanes and vehicles using I-70 Mountain Express Lanes outside operating hours. This is due to safety hazards presented when vehicles cross from the general purpose lanes, the narrow 11-foot width of the lanes, and the nature of the lanes being used as emergency shoulders when closed.

    Infographic demonstrating the three different types of Express Lane Violations and why the rules are in place (PDF) 

Penalty and Payment

Violations on the I-70 Mountain Express Lanes, C-470, and I-25 north of Denver will result in a $75 civil penalty. Violations not paid within 20 days of issuance will increase to a $150 civil penalty.

There are several ways to pay, including:

  • Online at
  • Make a payment with your notice number using our automated phone system at 1-(800)-450-5167.