Drivers, CDOT say Twin Tunnels detour flows smoothly |

Drivers, CDOT say Twin Tunnels detour flows smoothly

Caddie Nath

On Monday morning, Breckenridge resident Christine Scheel made her daily commute to Denver on Interstate 70 eastbound. As she approached the Twin Tunnels just east of Idaho Springs, traffic began to slow down and at times came to a complete stop, adding, she estimates, at least an extra 15 minutes to the drive.

Colorado Department of Transportation crews working on a highway expansion project at the facility had closed one lane of the normally two-lane detour around the work zone, causing the backups.

State transportation officials estimate blasting operations — when crews stop traffic completely for up to 30 minutes while using explosives to widen the tunnel bore — are roughly 75 percent complete and should wrap up by early August. But the lane closures, which at times can cause longer delays, are set to continue through the end of the year, when the project is scheduled to be completed.

But between the blasting and lane closures, the detour — directing eastbound cars off to the right, over Clear Creek and around the Twin Tunnels work zone — is causing very little trouble for drivers.

“I think it is working as well as can be expected. There are a lot of signs to help figure out where to go. In general, it has had less of an impact on my commute than I had anticipated.”
— Commuter Christine Scheel

“It flows pretty smoothly,” CDOT spokesman Bob Wilson said. “The only thing that creates some problems is when we have lane closures. Blasting hasn’t been the biggest issue.”

When both lanes are open, traffic is able to move reasonably easily around the curved detour using a restored frontage road nearby, and any time lost is generally due to the 35 mph speed limit.

“I think it is working as well as can be expected,” Scheel, who commutes from Summit County to Denver four days a week, stated in an email. “It changes overnight sometimes, so that can get confusing. But there are a lot of signs to help figure out where to go. In general, it has had less of an impact on my commute than I had anticipated.”

While blasting schedules are rarely available in advance, CDOT does set lane closures through the Twin Tunnels work zone ahead of time.

This week the left eastbound lane will be closed from 5-11 a.m. today through Friday and until 10 a.m. on Saturday. The left westbound lane will be closed overnight tonight and left lanes in both directions will be closed overnight Thursday.

The $106 million Twin Tunnels project will add a third lane to I-70 eastbound along a four-mile stretch that was recognized as a traffic bottleneck, adding to severe congestion that builds up particularly on Sunday and holiday afternoons during peak tourism periods for mountain resort communities. I-70 is the primary travel route between the Front Range and the mountains.

One lane will also be closed in both directions at night through August at the Eisenhower Tunnel for sweeping and maintenance operations.

Information on lane closures and traffic impacts is posted online at

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