Sorry, i was out for the evening.
Those types of bridges would bother him. The trainer said to take him to a big, wide bridge to start with.
My theory is to begin where the stress level is the lowest. If he has no reaction to small garden type bridges, then you'd have to find where his threshold is.
If he is going to react to small bridges, then starting in your back yard would be a good idea. If he is relaxed and confident in your back yard. I'd suggest to begin with a large plank or board and just lay it in your yard. You ignore it. Don't try to coax him to it or go over it. Let him get used to it in your yard. Once he ignores it, play games over it. Throw a toy, lay a food track..that sort of thing. Try to keep his stress level as low as possible.
Once he is confident over that, then using the same material, raise it. Make sure what ever you use to raise it does not compromise the stability of the board/plank (bridge). Start over again by you ignoring it (you're not recognizing any danger or threat in the 'bridge') and let him investigate it using his own time line. Make sure you throw a party and treat/praise when he approaches or goes over it on his own. If he is food driven, laying a food track would help him take this next step.
Keep advancing your 'bridge'. Once he is confident over the one you built at home, then take him to a play ground. Use their equipment.
You might want to pay special attention to the material you use. You don't want it to make noise (plastic) or be slippery in the beginning.