Traffic along I-70’s mountain corridor west of Denver has a significant “tourist” component to it. Congestion is heaviest on Saturdays and Sundays, during winter and summer. At almost all other times, congestion is non-existent. As a result, Colorado Department of Transportation (CDOT) and its regional partners (Clear Creek County, Summit County, and various municipalities) have struggled with the right level of investment in this corridor for over a decade. The nature of the corridor lends itself to very costly infrastructure expansion; however, the current infrastructure has proven to be greatly inadequate for providing peak level capacity – a 1 hour trip from Summit County has shown itself to take over 5 hours during peak demand conditions compounded by weather. As one commenter stated from the article above, “Something has to be done… This is so insane every Sunday.”
Putting aside the multiple billions of dollars required for expanding I-70 to the mountain areas, CDOT has responded in ways that it can, given available resources. It is currently wrapping up the expansion of the “Twin Tunnels” near Idaho Springs to allow for three lanes in each direction. And, CDOT is currently expanding eastbound I-70 between Empire and Idaho Springs through a widened shoulder. In off-peak periods, I-70 will have two lanes and a shoulder. In peak periods, the shoulder converts to a toll lane — all controlled through overhead lane use signage.
This article by KUSA in Denver provides a good articulation of both the improvement and what it will cost to use the lanes.