Widened I-70 tunnel to get new concrete lining

Construction crews are preparing to install the concrete lining on a newly widened tunnel on Interstate 70near Idaho Springs.

The Summit Daily News reported Wednesday it took 85 detonations to widen the westbound bore of the Twin Tunnels from two lanes to three.

Only two lanes will be used until the highway on either side of the tunnel can be widened. State officials say they saved money by widening the bore early because equipment was still in place after the eastbound bore was expanded.

Work on the eastbound bore finished last year.

The $55 million expansion is part of a long-term project to improve traffic flow on the congested highway through the heart of the Colorado mountains. I-70 links Denver to some of the state’s biggest ski areas.