I had the distinct displeasure of having to drive to Ogden from Phoenix this last Saturday. I ran into a few nasty conditions that I don't wish on anybody. At one point I was stopped on I-15 at the summit near exit 120 for over an hour. I saw more than a half dozen tractor trailers with the trailers askew as the rear of the trailer slid to one side when they stopped. I saw one veteran driver give tire chain pointers to an obviously very young truck driver pulling a flatbed. Good to spread the knowledge.
After crawling down the hill from the submit, I saw what appeared to be a Chevy Tahoe on its roof in the median and a quarter mile past that, a Jeep Wrangler on its side. The emergency vehicles were gone and the overturned cars left as reminders until they could be retrieved in better weather.
At one point between Nephi and Spanish Fork, some driver decided to stop halfway in the right lane and shoulder. I was getting passed on the left and ending up sliding quite some distance only to stop 10 yards from the "pulled over" vehicle. I was able to straighten myself out and keep moving.
So, given their familiarity with winter driving conditions I was amazed at the number of vehicles that did not bother to turn on their headlights. Is there some rule about driving in snow during the day that you don't want to be seen? I know in Arizona, during the dust storm season, it is recommended that when you pull off the road (as far off as you can), you turn off your lights so that people don't follow you.
As a side note, the Rain-X Spray on glass cleaner works really well. Especially with the new windshield wipers I put on before the trip. I never had visibility problems out the windshield. Oh, and non-freezing windshield washer fluid. All three are a necessity before a trip with possible snow and rain.