No fewer than five planned blasting operations at the Twin Tunnels construction site had to be canceled this week due to a succession of snowstorms that brought several feet of snow to the High Country.
The project to widen Interstate 70 and the eastbound tunnel bore to accommodate a third lane of traffic is on a very tight schedule, but Colorado Department of Transportation officials say crews plan for weather delays and will be able to make up the time lost.
"It hasn't affected the final completion, but it has delayed some of the initial preparatory work," CDOT spokesman Bob Wilson said. "They'll be able to catch up once the weather warms up. That's the kind of thing they can make up in pretty quick order."
Workers, who are using explosives to expand the tunnel bore, planned to blast six times in the last week, but were able to blast only once.
The storms also put striping operations on hold, forcing crews to make up the work during heavy traffic. They are working around the clock six days a week in an effort to complete the bulk of the $106 million project by December.
But transportation officials say even on a tight schedule, they built in makeup days to adjust for delays caused by the snow.
"It's not like it's southern Arizona where you can be assured of the same kind of weather," Wilson said. "They always plan ahead that there's a good possibility of losing a few days to adverse weather, especially in the mountains."
Eastbound traffic is currently being diverted around the construction site on a 35 mph frontage road. Traffic has to be stopped in both directions for up to a half hour for blasting operations.
Transportation officials said they hope to have the project completed in a single construction season to help minimize the traffic impacts on the already congested I-70 mountain corridor during peak travel times.
The purpose of the project is to help reduce that congestion - which is at its worst in the eastbound direction on Sundays and holidays at the height of the ski and summer seasons - by widening the highway in a bottleneck area just east of Idaho Springs.
The new third lane will continue through the tunnels to the base of Floyd Hill, where it will join an existing third lane that runs all the way into Denver.
"We're chasing that three-lane section back four miles," CDOT engineer Jim Bemelen said.
It's the first in a series of far-reaching projects planned to reduce traffic on the I-70 corridor.