The only real problem that I had was that there is a drainage ditch along the road at our field. Everyone just parks along the side of the road before the ditch, then there are 2 waqlking bridges across. Well, the bridges are too narrow for a wheelchair so I had to go around the ditch. This year they put a length of culvert pipe in the ditch and backfilled part of it so I can just back my truck across and I'm right there. Makes everything much easier.
Most fields probably don't have a situation like this, but it doesn't take much to make things accessible.
Ben