Work on the westbound Twin Tunnels expansion project is under way, and drivers can expect more delays this summer as the Colorado Department of Transportation works to complete its latest attempt to alleviate traffic congestion on the I-70 mountain corridor.

The project follows the recent expansion of the eastbound tunnel and will help CDOT to accommodate future expansions of the I-70 mountain corridor.

Crews will be blasting the inside of the tunnel as well as the rock faces at the entrance and exit of the tunnel to allow for the expansion.

Off-peak closures of the roadway will be implemented in the coming days, as crews work to divert westbound traffic through the recently completed eastbound tunnel and move eastbound traffic onto the detour route around the tunnels.

As the project gets into full swing later in March, traffic delays will be put into place to halt traffic while crews blast the rock faces. Traffic will then be escorted through the tunnel to ensure public and worker safety.

Traffic delays could last anywhere from 15 minutes to 30 minutes during March. April is when CDOT will begin the major blasting operations that will stop traffic at 45-minute intervals, meaning traffic will be stopped both directions for up to 30 minutes while blasting is completed, then traffic will be moved through the tunnel for 45 minutes before being stopped for another 30 minutes.

The rock blasting on the west side of the tunnel will take about three months to complete, said Matt Hogan, project manager for Kraemer/Obayashi, during a March 13 telephone town hall meeting. And blasting on the east side will take about five months to complete.

Kraemer/Obayashi was the contracting team that completed the work on the eastbound twin tunnel and was selected to complete the work on the westbound tunnel as well.

All blasting work will run concurrently and will be completed during the overnight and early morning hours when possible, though the blasting on the rock faces on the outside of the tunnel will need to be completed during the daytime in order to comply with federal law and safety standards, Hogan said.

CDOT officials have said they will not be completing blasting work during peak traffic times, including Friday afternoons.

During the telephone town hall meeting, members of the public voiced concerns and questions about the project, including concerns about the timing of the project and the fact the project was started while ski traffic still congests the highway.

CDOT officials cited wanting to make sure they had enough time to complete the work before the weather hindered their ability later on in the year.

The project is being completed following completion of the eastbound Twin Tunnel because CDOT plans to save $5 to $7 million by not having to move the equipment, resources, and detour that are already in place.

While CDOT does not have immediate plans to add an extra lane of traffic through the tunnels, widening the tunnels should improve the flow of traffic as motorists will be less likely to slow down when approaching the tunnels.

Reid Tulley can be reached at 970-887-3334