Winter travel in the Mountain West is a regular topic here so I thought it useful to post some current observances here.
I am on day one of my family's annual ski/snowboarding vacation to the Park City, UT area. Our most gracious host provides us with ridge-top accomodations overlooking I-80 at a point between the Jeremy Ranch and Kimball Junction exits. This stretch of I-80 carries 100% of the traffic between Salt Lake City and environs (SLC) and Park City (PC), which includes 3 major ski areas with an aggregate of over 10,000 acres of ski terrain. The daytripper traffic from SLC to PC is heavy, as is commercial and noncommercial Interstate traffic.
Just west of my view is Parley's Summit, where I-80 rises to some 7,500' of elevation as it passes through the Wasatch Range, where peaks reach +11,000'. Parley's is the "crux move" enroute from SLC to PC. I-80 is 3 lanes in each direction from the outskirts of SLC all the way to and over Parley's, going back to 2 each way at the Jeremy Ranch exit. The total length of 6 lanes on each side is some 15 miles.
We arrived yesterday at 10:30 local time and our sons were eager to do the "ski free the day of arrival", a neat program where your boarding pass is your lift ticket for that day. We picked up an SUV and hurried them directly to Park City Mountain. On the way up (and it's only about 10 miles from the airport to the mouth of Parley's Canyon, where the 3,500' ascent to the Summit begins), we got into snow immediately upon entering the canyon. The level at which it was sticking to the road was at approximately 5,000'. It took about 1.5 hours to drop them off, hit the grocery store, and have a quick lunch, and my wife and I returned to SLC to pick up rental gear and discount lift tickets (what can I say, I'm Scots-Irish). On the way back down, the rate of snowfall had picked up considerably and we were able to make only 45-50mph going down. The "snow on the road" elevation had decreased to just over 4,000'. Within just over an hour, say starting at 3:30, we headed back up out of downtown SLC (and here, Mark, is an unabashed plug for Canyon Sports in SLC. Sorry about that).
The snowfall had started in the valley floor as we arrived at Canyon Sports and in only 30 minutes had covered our car and was sticking on the streets. It was a good inch-an-hour rate of snowfall. Traffic was moving slowly as we headed back up. At the mouth of Parley's, we encountered the first wave of plows headed down. The Utah DOT now uses just two plows, en echelon, to clear all 3 lanes. Each plow has "wings" out to the side, tandem axles, and chains on both rear axles. For a truck lovin' redneck like me, it's an awesome sight. We reached the approx 5,000' level and encountered a second wave of plows headed down. Moments later, we got behind the plows headed up. The plows necessarily had all uphill lanes blocked but were traveling 40-45 mph. As I anticipated, they summited the pass and plowed the east side to Jeremy Ranch, then turned around. As they exited, we saw a 4th pair of plows entering I-80 headed back to SLC. Clearly the MO was to keep 4 pair of plows in continuous motion on both sides of the pass all the way from SLC to just outside of PC. I doubt there could be more than 20 minutes between passes at any given point.
The point of this narrative is this: Interstate highways in the Mountain West are lifelines for local and regional economies. Extraordinary efforts are required and mounted to keep them moving. Yes, there was snow on the roadway in each direction, but neither chains nor 4WD was required. As it got dark, thousands and thousands of skier vehicles departed PC and headed back over Parley's to SLC. Traffic in that direction never appeared to get below around 35 mph.
As I look over the highway currently, at 7:30 am Tuesday, traffic seems to be moving at normal speed, likely the result of all night UTDOT plowing and salting. This entire event brought between 8 and 16" of snow over a 12 hour period, and the temprature never got above about 20 degrees.
So, keep your eyes open, drive carefully, keep legally-required gear on board (most often chains), be aware travel speeds can slow down during an event, and be aware travel apeeds can actually stop for brief periods. But, don't shy away from highway travel in the Mountain West just because it might snow. It's GOING to snow, but you're going to be fine.
Foy
{Adding a link here for a day trips article that includes information about the Park City Route. As an aside, I usually approach Park City from the south -- and that route is nearly always a bit icy....}