The California Department of Transportation District 2 today issued a traffic advisory for a potential increase in traffic on Interstate 5 in northern California the weekend of July 20-22.

Several factors are cited, including people traveling to Mount Shasta for Saturday’s Pacific Crest Trail Town celebration and restrictions resulting from current highway construction from Dunsmuir through Mount Shasta.

That road project, repaving a stretch of I-5 with concrete, is in a “critical construction phase,” according to Caltrans, including lane closures, detours and no alternative routes.

Traffic delays are anticipated on weekends from 30 minutes to 1 hour. The critical construction phase is scheduled from July 9 through the end of August. A lane will be reopened after that, and the project continues until its anticipated completion in 2020, for a total of two years of construction, according to a Caltrans press release.

Caltrans says motorists may see an increase in I-5 traffic northbound on Friday and an increase southbound on Sunday.

It advises the traveling public to “be patient and have water and snacks especially if traveling with children.”

Other factors cited for increased traffic are the high traveling season and an ongoing increase of large commercial vehicles.

For traffic updates see Caltrans District 2 Facebook and Twitter.