This is sort of the 800 pound gorilla questions. I believe in arizona
the rider has the legal right of way. The rider is also responsible if they
cannont control the horse and it violates traffic law, (e.g. bolting when
someone honks or waves) and causes an accident. I have to ride on the surface
streets a little bit sometimes to get to t our local trails, and legal or not,
the 800 pound gorilla always has the right of way. there is no contest between
the horse and motor vehicle in the event of an dispute over who gets to use the
roadway. Pedestrians always have the right of way here as well. But who would
care to force the issue. forget what is legal and follow your instinct in
every situation where you feel threatened.