I-70 Mountain Express Lane

The I-70 Mountain Express Lane—the outcome of the peak-period shoulder lane (PPSL) project—runs eastbound on I-70 from Empire through the Veterans Memorial Tunnels to Idaho Springs. The lane is only open weekends and holidays, and is a shoulder lane when not in use.

I-70 Mountain Express Lane entry sign

The I-70 Mountain Express Lane project upgraded 13 miles of eastbound I-70 within CDOT's existing right-of-way. This work created a wide shoulder that operates as a third travel lane along eastbound I-70 from Empire through the Veterans Memorial Tunnels to Idaho Springs.

Rather than being open all the time, the lane is open for up to 100 days per year when the highway experiences the highest traffic congestion (primarily holidays and weekends). This provides much-needed relief to the busiest recreation highway in the state. When the lane is not open, the overhead signage indicates that it's closed and is being used as a shoulder.

Since opening in December 2015, the Mountain Express Lane has relieved traffic congestion, diverting 750 to 900 cars from the free general-purpose lanes. This alleviates traffic congestion in the Express Lane, and decreases congestion in general-purpose lanes and frontage roads. The lane reduces travel time by nearly half from the Eisenhower/Johnson Memorial Tunnels to the top of Floyd Hill, resulting in an average time savings of 30 minutes.

CDOT, local communities and travelers are benefitting from the I-70 Mountain Express Lane via decreased travel times and faster, more consistent speeds. The lane has also helped reduce congestion due to traffic incidents.

Prior to the I-70 Mountain Express Lane opening, traffic on eastbound I-70 between US 40/Empire Junction and the Twin Tunnels could be delayed up to 2.5 hours for an eight-mile stretch.

Crews on this project expanded eastbound I-70 from two lanes to three between Idaho Springs and Empire. That additional lane—the shoulder of the interstate—now functions as a tolled Express Lane in which motorists can travel during designated times, determined by traffic volumes.

  • During normal traffic, the Express Lane serves as a shoulder.
  • Improved signage alerts motorists when the Express Lane is open.

Since opening, this and other Express Lanes across the state have moved people and goods faster during peak travel times.