Set yourself up for backing in as you approach the site. Rig parallel to opposite edge of road, four ways flashing. Cut wheel and aim tow vehicle directly for where you will back in. As tow vehicle passes opening, or a little past, turn back toward opposite side of road. Watch trailer in mirror as back end of trailer passes opening, cut wheel back other way so rig is already articulated and aimed at your spot. Sometimes there isn't enough room to do it any other way.
Takes a time or three 'til you figure out how the wheel base is going to play together. A short trailer with a long truck will be hard to chase backing up, easy to jack knife. The longer the trailer the easier to chase, but you need more room to cut an arc. Carefully consider what you do with the wheel when pulling up to increase or decrease arc.
When learning how to back a trailer, it helps to grip steering wheel at bottom. No mental gymnastics trying to remember which way to turn the wheel to do what you want, just move your hands the direction you want the back of the trailer to go. small or slow adjustments of the wheel work better than large flailing of the arms.
The object of the set up manuever is to set your rig already aimed to cut an arc into your spot with minimal input from you.
Don't hesitate to get out and look around. Last I knew, CDL A road testers encourage three get outs and three pull ups per maneuver. However they don't allow a set up maneuver. Have never even been looked at cross eyed by a LEO for it though.
Hope that helps.
Bill
