what type of ROW? If its a utility ROW - you aren't supposed to be riding ATVs on them and the owner (Eversource and/or gas company) would not support that. In addition, if you called them and complained that people are using their ROWs for access - they may be willing to go up and post it etc. but I'm not sure that helps you too much.

As long as the owner of the property is doing everything by the books, I don't think there is much you can do as an abutter.