Hi Eleanor

I don't know if my suggestion is any good or not but would it be poss to have someone bring a truck or heavy vehical in and have it sitting in a safe environment (like an enclosed yard or manage) with the engine running and then use the dually and the advance and retreat method in hand rather than trying on the road (which sounds very dangerous) or in the field where the truck is zooming past and is gone - this way you can work in little steps to bring him closer then reward him by going away when he is brave eought to take that step, also the vehical would be stationary and not 'coming at him' once he can handle going nearer the vehical then perhaps you could start the vehical moving slowly and then build up to doing this in the field near to the fence where the road is - this way you are still in a safe environment rather than a road where if it goes wrong it could be tragic

Hi yes I thought of your suggestion but dont know anyone who owns a truck that I could bring in & leave for a bit. They all seem to be in use. When a truck is stationary on the side of a quiet road, I have taken him walking around & around & he doesnt seem to mind. He will sniff it & examine it. Even when the engine is running he doesnt run away it seems more when the truck revs up or is at speed going past him. Do you think it would be more effective on the ground using the dually halter rather than riding?

In my experience it's usually the "big thing come trundeling towards me, making lots of noise" that is the really scary part.
If you are stuck with training on the roadside, I would start in the dually on foot, rather than be thrown and hurt and have a loose horse on the highway.
Have you tried walking him while you wait for a truck to come by? Maybe at some distance at forst, since he doesn't mind them from 30 yards or so - and then move closer?
Get his attention and ask him to concentrate on what YOU ask, rather than on what's around him.
What you really want to do is to teach him to NOT pay attention to trucks - they're just props on the road. If you stand there pointing him to them, I think he is bound to overreact a bit.
Good luck!!

You can desensitize the horse: begin with an electrical device to clean teeth, then louder motors (saw), normal car and finally the truck, first at a big distance, coming closer. To decide how far you can go is not easy, maybe you need somebody with experience. Doing it the wrong way you may sensitize the horse getting things worse.
Rudy

This can be a hard problem to solve, especially if the horse experienced some pain associated with the noise. Not necessarily pain of a wound but pain of being in the ditch immobile and extremely vulnerable as the terror passed. To solve the problem you probably have to re-create the incident as near as possible. Of course in a safe environment for you and the horse. A number of things happened in an instant of time. A big scary object came up behind him out of nowhere and was chasing him. The big thing made lots of scary "growling" noises. The big scary thing immobilized him and took away his power of flight and hurt him. Of course all these things didn't really happen. The school bus wasn't really chasing him. The noise wasn't the growl of a predator. The horse really wasn't physically hurt by the incident. However that's probably the way the horse perceived it.

To solve the problem you have to undo all those perceptions. I would suggest first to put a work bridle on him, a bridle with blinders. Then take him to a road with truck traffic and stand him as close to the road a safety permits with his rear toward on-coming traffic. Be sure to make safety number one. Be sure to put the Dually halter under the bridle so you can keep control. The first few passes by trucks may incite lots of action. Slowly the horse should quiet. When it no longer pays attention to the traffic coming up from behind him and allows you to move him close to the road you can move him back to his "safe" zone and remove the binders and slowly move him closer to the road keeping him parallel to the road and his rear toward the on-coming traffic.

Two additional things that might be useful in preparation to the above is to find or make a CD with a lot of truck and road noise on it. Set it up near his stall and play it over and over until he ignores it. Another is to find a truck or large vehicle that has the motor running and back him toward it a number of times on both sides using the Dually halter. You want to create the sensation that the object is coming up from behing the horse. Leading him up to the source and letting him smell it and even touch it doesn't really teach him much. A horse may be cautious but it is not generally fearful of things that don't appear theatning and the horse feels that it can escape. To solve the problem you have to recreate the incident in the horses mind and then desensitize him to it. To us we may think " Why is this horse afraid of a harmless, noisy school buss that is just driving down the road". The horse sees it as "Oh my God! That big predator came out of nowhere behind me and is attacking me and wants to eat me. It's making a horrile growling noise and forced me into the ditch so that I was at it's mercy. Thank goodness it ran away". Of course horses don't think and reason in those terms but that is how the horse perceived the incident. The task is to convince the horse that his perception is wrong. It can take a while when a high level of fear is involved.