My sister is a Horsey type. When she got married their first house was in Sylmar near the mountians and right next to an open field. Neadless to say they rode there a fair amount, not just riding but also to get to trails. There were dirtbike riders also (motor, not our kind). Most of the time when it was kids they would back off the gas whne near the horses. Not the same for adults, some of whom would rev their engines when passing.