Why It Could Cost You $21 to Use Express Lanes from Denver to Boulder

Depending on the time of their commute, drivers traveling between Boulder and Denver using express lanes on Interstate 25 and U.S. 36 could be paying more mere weeks from now under a new proposal by Plenary Roads Denver, the private concessionaire that manages the lanes in conjunction with the Colorado Department of Transportation. The price tag for people who don't use Express Toll — the service that automatically assesses fees rather than mailing bills based on license plates — could be as high as $21 to travel the route, more than $5 higher than the proposed toll rates less than two years ago.

According to Megan Castle, communications manager for CDOT, adjusting toll rates is "the only way to manage congestion.... If you're in that lane, you expect a reliable travel time, and if too many people are using it, we price it higher to decrease the amount of cars going in there. But in some places, the price will actually go down to reflect the usage of the lane at that time."

A CDOT summary of the proposal that will go before the High Performance Transportation Enterprise board during a meeting later this month (details below) illustrates the range of prices. On average, tolls along U.S. 36 will go up by 10 cents for Express Toll customers driving at times considered off-peak, or outside of morning and afternoon rush hours. At peak times, the Express Toll fees will go up by an average of 15 to 35 cents, though some locations will see decreases of 10 to 60 cents. A round trip from Boulder to Denver will cost Express Tollers 35 cents more than before, based on a 40 cent decrease during morning rush but a 75 cent uptick in the afternoons. The maximum morning price for Express Toll customers will be $8.35 under the new plan, with the afternoon drive maxing out at $8.05.

Express Toll rates are consistently lower than the so-called License Plate Toll rates, and this pricing structure is intended to convince regular commuters between Boulder and Denver to sign up. "You'll save money every time," Castle points out. But the costs in both categories have risen considerably since the lanes were put in place, as seen when comparing the following two CDOT graphics for toll rates between Table Mesa and Denver.

First up are the rates as seen in an October 2015 document:

And here are the new proposed rates:


As you can see, the rates are lower in 2017 than in 2015 for Express Toll users traveling at "morning low peak" (from $6.50 to $3.30) and "morning high peak" ($8.75 to $8.35). But in every other category, the price is higher for Express Toll users: "mid-day" (from $1.25 to $2.45), "afternoon high peak" ($3.75 to $5.15) and "weekends" ($1.75 to $2.45).

The contrast is even greater when it comes to License Plate Toll rates. Again, there's a decrease for "morning low peak," from $13.85 in 2015 to $12.45 in 2017. But "morning high peak" goes from $16.28 to $21.55, more than $5 higher, with increases of $2.80, $7.10 and $2.80 for "mid-day," "afternoon high peak" and "weekends," respectively.

Castle stresses that the higher prices aren't simply intended to generate more revenue. Rather, they're about maintaining quality and altering behavior. "We have an agreement with RTD that their buses will be able to travel at an average of 55 miles per hour," she says, "and if that travel time isn't delivered, the price has to be adjusted. And if you're traveling in the express lanes, we want to make sure you get what you pay for."

CDOT argues that the lanes have already helped to improve congestion. On U.S. 36, they're said to have increased speeds during rush hour by 20 to 29 percent for everyone — not just those paying tolls. Moreover, people who carpool with at least two other people don't have to pay to use the express lane, and there's also a bikeway along the U.S. 36 corridor.

Thus far, Castle says, she hasn't received any significant pushback from drivers in regard to the proposed rate changes. But she adds that the public will be able to share comments at the aforementioned HPTE board meeting, scheduled to take place at 11:30 a.m. on July 19 at the CDOT Headquarters Auditorium, 4201 East Arkansas Avenue. If the board approves the proposal, the new rates will go into effect just five days later, on July 24.

One more thing: While this is the first time the board will consider rate changes, it won't be the last. "We're looking to do annual reviews of our tolls to make sure they're set properly," Castle says. "This is going to be part of the process for managing express lanes around our system."

For more details, click to access the Colorado Department of Transportation document "2017 Proposed Toll Rate Adjustment for US 36 and I-25 Central Express Lanes."