No Foolin': Traffic Shifts April 1 for Twin Tunnels Work

March 31, 2014 - Metro Denver Colorado/CDOT Region 1 - Crews will begin closing lanes in both directions of I-70 near Idaho Springs at 5 p.m. Monday, March 31, as work begins to shift eastbound I-70 traffic back onto the detour route around the tunnels.

This eastbound shift is slated to take place Tuesday, April 1. Once eastbound traffic is on the detour crews will move westbound I-70 traffic onto the eastbound side of the highway. This shift is scheduled to take place on Wednesday.

Those heading to Colorado’s High Country can expect travel delays and should plan for extra time beginning Monday evening when I-70 traffic is put in a head-to-head configuration through the westbound tunnel bore. Lane closures and traffic impacts will continue until Wednesday when westbound traffic is moved.

Once both directions of I-70 are shifted and traffic is no longer moving through the westbound tunnel bore, crews can begin tunnel blasting and rock face blasting work. Blasting activities require stopping traffic in both directions and motorists can expect extended delays when this work occurs.

The blasting schedule for the Westbound Twin Tunnels project will be aggressive and may cause heavy delays. Those traveling along the I-70 mountain corridor in both directions should anticipate longer travel times and plan accordingly. CDOT encourages people to visit, call 511 and/or download to CDOT mobile app for updated traffic information. You can sign up for text or email updates for each closure for this and other projects by visiting and clicking on the green cell phone icon. All scheduled lane closures can also be viewed at

Is it important to note that a detailed blasting schedule will not be included in the weekly lane closure report. In order to relay the most accurate information this report will be sent out daily via text and email alerts to those subscribed. On blasting days, traffic will be stopped in both directions for approximately 30 minutes. Following the 30 minute closure traffic will be released for approximately 45 minutes. After that time, traffic will be stopped for 30 minutes followed by a 45 minute release throughout the day for crews to perform rock scaling. This work is necessary to ensure the safety of the traveling public and also to keep the project on time as this is an aggressive construction schedule.

The Westbound I-70 Twin Tunnels project is part of a package of improvements designed to ease congestion on the I-70 mountain corridor. This $55 million project will widen the westbound tunnel bore in Idaho Springs to accommodate a future third westbound lane, but will not add a third highway lane at this time. With resources still in place from the 2013 project that widened the eastbound tunnel, it is estimated that doing this work now will save $5 million to $7 million. The new tunnel is scheduled to open to traffic by the end of this year and project completion is scheduled for the summer of 2015 when restoration work is finished on County Road 314.  For more information, call 303-327-4034 or visit For current road and weather conditions you can also text CDOT to 25827 or download the CDOT mobile application to your smartphone.