Seasonal road is a legend item on paper maps. The user would be expected, given the climate, to understand the closed season to be winter. In other climates it might be that the road is not passable due to spring flooding.

If a paper map has that feature Google maps should have it as well. It of course can have more features and _can_ be integrated with some kind of a weather + traffic warning system. But it doesn't have to. The way I interpreted the original comment was that the road had snow on it and user was baffled how come Google Maps didn't know about it.

I updated my post to note that it was a no winter maintenance road. I originally took some liberties assuming that most people would recognize it as such, but I guess those who don't live in extreme climates may not be familiar with them.