DENVER — Traffic rerouting on westbound Interstate 70 began Monday as the Colorado Department of Transportation began widening a portion of the Twin Tunnels near Idaho Springs.
While the eastbound approach to the Twin Tunnels was expanded to three lanes last year, there is no third lane planned for the westbound approach.
Workers will use blasting to widen the westbound bore, meaning traffic must be rerouted from the westbound side into the eastbound side. Crews will put down temporary pavement in the center median on both sides of the tunnel to transition traffic into and out of the eastbound lanes, CDOT said.
The work will take about a month to complete, and is expected to cause traffic delays, CDOT said.
The work is part of a $55 million series of projects aimed at easing congestion through the mountains.