Those were my favorite signs to see when I was up there.
That doesn't mean the roads are closed, though, does it?
Also, I have to concur about the financial bath part...
No, there are other signs that the towns post, quoting RSA's. That was the one I had a pic of though.
It is not a law, but towns have the right to do this and that, one of those things is closing at certain (or all) times. I prefer to follow those signs rather than be the cause of the road being closed to wheeled vehicles for good.
I can go center state and find some roads though, I just personally don't get into the mud season thing, ruts up the roads, then the greenies come screaming, and the road is closed. So, even the ones where it is "okay" I will not go until it is far more dry out there. At this rate, with the light winter and lack of rain, we will be out on those by May at the latest.