I found this to be an unusual thread. I have 4 grave sites I visit every year. In total, there are 22 people interred there, from my parents, grandparents and all the way back to great great grandparents. When I pray I always stand on their graves to be close to them.
I'm not a runner, but I would think that running between the headstones would be a hazard. Thus, if I did run I would use the road.