Legal Question in Real Estate Law in California

This sounds similar to a private-road situation I had years ago. Fortunately, no one challenged anyone else's right to use the road, and when the private road needed repairs, most of us were able to meet together and figure out how to split the cost. Later, someone (not I) figured out that our association was long abandoned and its paperwork a mess, and so by cooperation we gradually straightened that out too. It turned out to be to everyone's long-term advantage because, when it came time for anyone to sell, prospective buyers were always asking about the road and were relieved to know we had a generally functional association (it wasn't perfect, there will always be a few grouches).

You didn't really say explicitly whether the problem here agreeing on and paying for repairs, or your right to use the road, or maybe both. It would also be helpful to know whether there are existing disputes. However, I think some things you should consider include (1) having a neighborhood meeting to discuss documentation, use, maintenance, etc.; (2) retaining a local real-estate attorney to assist in doing a title search, a review of the road association documents (including formation documents if anyone can find them, and minutes of meetings), and advising on how to run this road in a more businesslike way in the future.

I would add that approaching the situation in a friendly and problem-solving manner is going to be cheaper and quicker than being litigious and confrontational, and let's hope the neighbors feel that way too.

Finally, if ultimately it turns out that you have access and use problems, remember that you may have gained a prescriptive easement to use the road through years of use without anyone's complaint.