Thought I'd add that just because it's a snow emergency route, that doesn't mean it will be safe to travel. It just means that they will try to clear it a little bit faster. I traveled on a snow emergency route to go 5 miles home from work last February. It took 45 minutes, in first gear the whole time, sliding along through 4 inches of snow.
These routes tend to be enacted after one-off severe storms, then forgotten. As another said, they're more likely to have stringent parking regulations than to be passable during a storm. Also, the first road to have abandoned vehicles towed away after the fact.
Someone correct me if I'm wrong, but State Roads are snow emergency routes. The only other roads I've seen marked a SER were the block the fire chief lived on and such.
IamSauerKraut t1_izx7zxi wrote
There are state-level snow emergency routes and municipal-level snow emergency routes.