40 one way at the end of the day is a lot to ask for. If I had to drive 40 min one way after I worked, ride, and then drive another 40 min home. I would never see my horse. Not because I didnt want to see him, but it would be too much of a pain to do on top of everything else I have to get done.
Why not try sitting them down in the beginning of the week and talking about setting a schedule for that week. See when they are able to take you, rather then asking spur of the moment. That way they can plan on taking you and not have to jumble everything else around. Some weeks they may only be able to take you once, other weeks maybe a bit more. You can also ask them what YOU can do for THEM during the week that will in turn make it easier for them to take you to the barn. Help cook dinner, help clean, it goes a long way.
This is what happens when you have democrats in office