Colorado’s most expensive toll lane, the I-70 Mountain Express Lane, to open |

Colorado’s most expensive toll lane, the I-70 Mountain Express Lane, to open

Elise Reuter
The Summit Daily News
The 13-mile tolled express lane on Interstate 70, stretching from Empire to Idaho Springs, features a fluctuating toll for a shoulder designed to function as a lane 73 days per year.
Courtesy of the Colorado Department of Transportation | Colorado Department of Transport

how the lane works

Where is the lane?

The Express Lane stretches between Empire and the Veterans Memorial Twin Tunnels east of Idaho Springs. It has two entrances, allowing users to enter or exit at Idaho Springs if they wish.

When will it be open?

The lane is set to open Saturday, Dec. 12, weather permitting. It will be open 73 days out of the year, on weekends during the ski season and busy summer holidays.

How much will the toll cost?

The toll can fluctuate between $3 and $30, depending on congestion (or demand). The rate will be displayed on electronic signs approaching the toll lane, and you will be charged that rate when you enter the 13-mile Express Lane.

How do I get a transponder?

A transponder may be shipped to you after setting up an account with ExpressToll online. The cost to set up an account is $35, but future tolls will be deducted from this balance.

Comparing the cost per mile:

I-70 Mountain Express Lane: Ranges from 23 cents to $2.31 per mile.

E-470 Tollway: About 30 cents per mile.

I-25 HOV Lane: Fixed variable rate with maximum of 66 cents per mile (Carpooling is free).

How much would you pay to ensure a speedy return from a weekend ski trip? How much to catch a flight at Denver International Airport?

The Colorado Department of Transportation will weigh these factors in upcoming weeks as it conducts test runs of a new express lane along the state’s notorious Interstate 70 Mountain Corridor.

The long-awaited I-70 Mountain Express Lane, touted as a solution to the corridor’s congestion issues, is set to open today. The lane also is gaining another reputation as one of the nation’s most expensive toll roads, with a fluctuating toll rate capped at $30 for the 13-mile stretch of road, to the tune of $2.31 per mile.

While the bulk of construction work for the project is complete, the CDOT is setting aside the next two weeks to test the new infrastructure, including electronic signs, license plate cameras and tolling equipment.

CDOT communications director Amy Ford said the department also would conduct a few “dry runs” to gauge toll prices, which will vary from $3 to $30 depending on demand.

“There is no other express lane built on the idea of recreational weekend travel,” she said. “Those people traveling the corridor at that time are people who have made an investment in recreation and now have an opportunity to make an investment in their travel time coming home.”

By nature, the lane would mainly target Front Range residents, who often head to the mountains for a weekend of skiing and return east in time for the work week. Open 73 days per year, the express road will function as a toll lane on summer holidays and ski-season weekends. The remainder of the year, it is intended to be used as a shoulder.

“It is not a full, brand new lane. The solution is temporary in nature,” Ford said. “We hope it will give us 5 to 10 years to develop more permanent options to address issues in the corridor.”


The 13-mile shoulder-lane, stretching between Empire and the Veterans Memorial Twin Tunnels, is intended to address a small segment of I-70 that is particularly prone to congestion.

Not only did the eastbound lane have a shoulder to more easily construct the lane, Ford said, but the downhill direction also sees slightly worse congestion than westbound on weekends.

“People change the times of when they come up to go skiing,” she said. “(Traffic patterns) are much more consistent eastbound. You’re seeing people flush out at very particular times.”

According to CDOT’s statistics, traffic in the “pinch point” peaks between 1 and 3 p.m. on the weekends. However, the congestion can start as soon as 11 a.m., as skiers head off the mountain early to avoid the worst of the traffic.

As an example, the toll sets the rate at a base of $3 for the morning. Into the afternoon, the price might jump to $8, rising to $10 by late afternoon when traffic is densest. Then it would drop back down to a $5 toll by the evening.

“It could flow up and down within that range throughout the day,” she said. “We’ll have to see what people’s price points are. We will be working and testing all of that.”

The goal is to use the pricing to maintain a volume of 750 to 900 vehicles per hour, guaranteeing a steady speed of 45 mph. Rates of 2,000 vehicles per hour lead to reduced speeds, and 3,000 vehicles per hour results in stop-and-go traffic. The hope is that the influx of vehicles into the toll lane would also assist with congestion in the two regular lanes, even if just by a slight amount.

The lane will be open to all two-axle vehicles less than 25 feet long. The road will not serve as a high-occupancy vehicle lane, however, and all vehicles that are able to enter will be required to pay a toll, either by attaching a transponder to their dashboard or by having their license plate photographed, resulting in an increased price to account for processing.


Ford said carpooling was not incentivized because the corridor is unique in that the majority of vehicles during peak periods already carry three or more passengers. So, creating an HOV lane would not significantly change traffic patterns.

The plan came together three years ago after a third lane was added to the twin tunnels east of Idaho Springs. The $72 million project is partially financed by state and federal funding as well as $25 million in loans from the state’s High-Performance Transportation Enterprise that will be repaid over a seven-year period using toll revenue.

However, even after the debt is repaid, the lane will still maintain a toll for the purpose of regulating traffic. Per standards, the remaining funds must be used for improvements to the toll lane.

Ford said that while CDOT would like to expand I-70 by one or two lanes in each direction and add a train as an alternative transportation option, the state simply does not have the money yet.

“We have a final decision document that says ‘Here’s what we would love to do to the corridor,’” she said. “However, in the short term, we wanted to do some quick-turn responses on how we could address issues in the corridor.”

CDOT currently has a $1 billion annual budget. The option to widen the I-70 corridor from Denver through the tunnel to Vail would cost between $3 billion and $4 billion, and the addition of a train, which would require a third bore through the Eisenhower-Johnson Memorial Tunnel, would cost a whopping $16 billion.

In a few years, Ford said, CDOT might look to add a similar express lane westbound, if they can secure the funding.