In southwestern Wyoming, I-80 is shut down in both directions from Evanston to Lyman, and was scheduled to remain closed until at least 2:30 a.m. Monday.
Most experienced Wyoming drivers know they need some essentials in their car during long trips like emergency repair kits, road flares, jumper cables, etc.
The Wyoming Department of Transportation says the 68 percent increase was most pronounced in Laramie County, which saw 209,394 vehicles more than average for the third Monday in August.
The influx of people is expected to clog 911 dispatch centers, fill up hotels -- many of which are already sold out, and have been for some time -- and overload cellular phone networks.
Last week when Wyoming received it's annual May blizzard, we asked if residents think interstate closures are a good thing or a bad thing for Wyoming's economy.