My gelding would much rather go out with other horses but we don't have that option at the moment so I make him do it anyway. He constantly tries to turn back but I just ride him through it. He did throw in a buck the first time we went down the road since moving to this yard, so I just made him pick up a good steady trot and work... go figure he didn't try it again since! :)
We dont have trails and just a road to ride on so we really only have cars, people and dogs to deal with. He does take it all in but in my 3 years owning him he has only looked at things, no spooking/bolting/ect *knock on wood*
Stop for a minute, open your mind, learn. You may not agree with what I say, I may not agree with what you say but we will both learn something new.