The appraiser should not be concerned with whether the loan is made or not. As I recall (haven't checked in a while), FHA requires that the property be accessible from an all season road. It it's a private road, they are going to want to know about maintenance. If there is a recorded maintenance agreement, report it. If there is a verbal agreement among neighbors, you say that. If there is no maintenance agreement, you say so. Our job is to report what is. The Lender's job is to decide whether to make the loan or not.