"Very heavy" traffic is expected on eastbound Interstate 70 through this evening as people return to Denver after holiday vacations.
Delays of more than an hour are possible, The Colorado Department of Transportation tweeted early Sunday.
Heavy I-70 EB Traffic 30+ min. extra travel time from Silverthorne to Denver/C-470;Total travel time approximately 85 min
— CDOT (@ColoradoDOT) January 3, 2016
The I-70 Mountain Express Lane, which is available during peak travel times, opened at 9 a.m., according to CDOT.
The 13-mile toll lane runs from Empire to Idaho Springs.
The toll lane fees range from $3 to $30, depending on traffic.
A crash briefly shut down the highway and Mountain Express around noon.