Driving You Crazy: Why are the mountain toll lanes on I-70 only open Friday to Sunday?

Dave from Littleton writes, “What's driving you crazy? Why are the toll lanes on I-70 only open Friday to Sunday? They seem to be closed every Thursday and Monday I want to use it. I understand the need for occasional maintenance, but they are closed more than open.  Maybe $3.00 on light traffic days would give them some revenue?”

The Interstate 70 mountain express lanes, also known as the peak period shoulder lanes, operate in both directions of I-70 between Idaho Springs and Empire. These lanes are not like any other travel lane. They are technically an interstate shoulder that have been converted into a travel lane. The compromise the Colorado Department of Transportation made with the Federal Highway Administration to make the change was to agree that express lanes will only open for a certain number of days and for a certain number of hours per year.

The eastbound I-70 lane is allowed to be open for 100 days and 1,168 hours. The westbound lane is allowed to be open for 125 days and 965 hours. When the lanes are closed to traffic, they return to being an interstate shoulder and are only to be used in an emergency.

That's why they are open mostly on weekends and not during the week when traffic volume is typically light.

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“We have historical experience with traffic patterns on these weekends and holidays, and we also monitor for weather conditions, special events, etc,” Tim Hoover, CDOT’s Deputy Director of Communications - Policy and Programs, said.

If you ask most people, they will say I-70 traffic volume is heavier in the winter than the summer. That is not the case. What affects winter traffic speeds more often is snow and crashes. I asked Hoover how much does snow on the roadway and the risk of a crash affects the decision to open the lanes or keep them closed for safety?

“This completely depends on the amount of snow and when it falls. Generally, we are able to clear the snow and open the lanes, even if that means a delayed opening," Hoover said. "If we are concerned enough about safety, we will close the lanes until we are sure they are safe to reopen. Accidents related to snow, a jackknifed semi for example, could result in part of all of the corridor being shut down for hours. It really just depends on severity.”

If you have ever driven in either lane, you know it is very narrow. There were times when I used it that I thought it was a miracle I didn’t bump into the wall. They are not as wide as regular highway lanes. Therefore, they stay closed when officials believe it isn’t safe to drive in them. Like Hoover said, there are times in the winter where CDOT determines that either there is too much snow on the roadway or some other factor that makes it unsafe in their opinion to open the lanes.

I remember back in 2023, Governor Jared Polis asked the Colorado Transportation Investment Office (CTIO), the division of CDOT responsible for operating, financing and constructing express lanes, to open the lanes for the Thanksgiving and Christmas holidays. At that time the governor also requested that CTIO revisit the total number of days when the lanes are open and if that number could be increased to meet future traffic volume. I asked Hoover where that request stands now that we are more than a year past the governor’s request.

“We are presently in the process of renegotiating the agreement with the Federal Highway Administration (FHWA) for more hours," Hoover said. "This also involves getting agreements from local stakeholders. While we are not yet ready to talk about what a new agreement would look like, we can say that we are very excited about it.”

Hoover did confirm this new agreement — when finalized — would increase the number of days/hours the mountain express lanes could stay open.

Tied into all of this is another developing trouble spot east of Idaho Springs. I’ve reported on the I-70 Floyd Hill project where CDOT is changing the layout of the interstate but also adding an express lane in each direction. Those express lanes will be connected to the current mountain express lanes. The problem lies with the new express lane connection to the current mountain express lanes. The new Floyd Hill express lanes are being specifically constructed to be an all-the-time express lane so when they open, they will be open 24 hours a day. However, they will feed into the mountain express lanes, which are still limited by the FHWA agreement. That could lead to a new bottleneck, especially on the westbound side of I-70, if drivers jump into the Floyd Hill express lane but are forced back into the general purpose lanes when the mountain express lanes are closed.

Other key points, specifically with the mountain express lane, it is a toll-only lane. You don’t get to avoid the toll using a motorcycle or being in a carpool. Large trucks or vehicles with trailers are not allowed to use the lane because it is so narrow. Same for RVs, semi-trucks or vehicles with three or more axles.

The tolls are adjustable, which means prices rise and fall to encourage drivers to use or stay out of the lane as traffic volume in the lane changes. CDOT said the change in toll prices keeps traffic moving.

Overhead signage just before the entrance to the lane will indicate the current toll prices. Tolls are collected through an ExpressToll account or License Plate Toll for a higher fee.

Denver7 Traffic Expert Jayson Luber says he has been covering Denver-metro traffic since Ben-Hur was driving a chariot. (We believe the actual number is over 25 years.) He's obsessed with letting viewers know what's happening on their drive and the best way to avoid the problems that spring up. Follow him on Facebook, Twitter or Instagram or listen to his award winning Driving You Crazy podcast on any podcast app including iTunes, iHeartRadio, Spotify, Podbean, or YouTube.