On the way to Las Vegas, I was shocked to be driving through a snowbound Mojave desert

 my first indication that it was very cold in the mountains between LA and LV. Turns out it was 32 degrees in Halloran Pass on the 15 north

 Obviously also going to the Mopars at the Strip 2012

 About the time I saw snow up to and on the freeeway, I started worrying about the traction ahead, because I doubt anyone coming from Southern California has snow tires, winter tires, all season, or anything but summer tires.

 People pulled over to have snowball fights were common

 Snow on the Joshua trees

 in the above photo, all that slush and snow in the left part of the photo? That is all the fast lane. No one was trying to drive in that, it was easily 4 inches deep

Notice that miles along, I'm still behind the same car, nothing was going very fast, no one was passing, and the left lane was a bad risk for ending up in the median ditch.