That's a great suggestion! Could you possibly share a sample waiver, i.e. one you've used, with specific information blocked out or with blanks to fill in?
I've seen one road association get a work day together, where a whole bunch of their members pitched in to trim back brush along the roadsides. Some brought chain saws, some brought clippers, and some loaded brush onto a trailer someone else had supplied. I thought it was a great idea! But when I suggested it for our road association, there were only a few people who showed any interest in being involved. So when there was a heavy wet snowstorm that bent the trees into the road, one couple spent a few days getting it clear. A couple of other people did the part in front of their own homes. But it could have been taken care of the previous summer.
I also know people who will run a York rake over their road, or knock out the ends of people's driveways after a snowstorm. If someone has farm equipment but is not a licensed and insured contractor, it seems there should be some way to allow them to help the road association save costs, without raising questions about liability.
In a similar circumstance, the Commission on Abandoned and Discontinued Roads is currently trying to figure out how to provide some liability protection for residents on discontinued roads, where usually there is no road association and no public maintenance, but the public can still use the road. So the resident or owner of abutting land has little choice but to do road maintenance if he wants to continue to be able to access his property. But public use can raise liability issues. At least on private roads, public use isn't part of the mix unless the road is also a public easement.