I own 14 acres. Two neighbors have an easement through one corner to get to their property. I never go there, so I have no idea what goes on there.

One neighbor called me and said they had rebuilt a culvert under the road on his property, 5 feet from the property line. While they were doing that they expanded the road for additional parking, partly on my property. The contractor pointed out that the parking would ruin the drainage, so they put in a roadside culvert through the parking area; again partly on my property.
The neighbor said he understood I probably didn't feel obligated to pay my third of the bill since I have no reason to ever use the road; but he just wanted to make me aware of it.
I told him he should have gotten my permission before doing any work on my property; he said there wasn't time.
He mailed me a copy of the bill, with my third written out.

Is this anything I should care about? Do they gain any right to my property by either expanding the road or putting in the culvert?