Visual Aid For Straight Line Backing

So school is going very well, Thanks to the High Road Training Program. And we will be working with instructors in the truck starting next week.

It looks as though we will be working on straight line backing to start. My question is, What do most drivers keep their eye on when backing?

Obviously the trailer and cones/dock. But is there a more specific part of the trailer? And as far as mirrors, Obviously you want to use all out in the real world for safety reasons, but in an empty parking lot just to get between the cones could I primarily focus on my driver side side mirrors?

Thanks, I appreciate any suggestions

Straight line, look for the same amount of trailer tires visible on each side helped me when i was learning. Also small adjustments.

... You want to use all (mirrors) out in the real world for safety reasons, But in an empty parking lot just to get between the cones could I primarily focus on my driver side side mirrors?

Use all your mirrors all the time. Cone practice is practice for the real world, so it's all mirrors all the time.

As for straight line backing, the trailer sides are all you need. When you back, if the trailer bows out of straight, turn the wheel a little bit toward the bowed in side.

Keep an eye on the trail end and landmarks near it so you know when to stop. Also, realize you're looking 60 feet to the rear of the the trailer so your distance comparison is messed up.

Absolutely do not just look at one mirror on the straight line backing. You need to be constantly moving your head checking both mirrors.

Heres how I teach my students this maneuver:

Firstly, if they have the bad habit of always over steering then I tell them to hold the steering wheel at the very bottom (palm facing the sky). This prevents over steering always.

Secondly, as you back up watch the back corner of the trailer. Keep the same amount of trailer on both mirrors (which is why you're checking both mirrors and not just one). If you start seeing more trailer in your passenger side mirror then you turn the steering wheel towards that side. If you see more trailer in your drivers side mirror then turn towards that side. Hold the wheel at the bottom and keep the movements very small. Make super small adjustments, you should never turn the steering wheel more than 1/4 of the steering revolution.

Hope that makes sense.

I appreciate the suggestions

That tip about turning the steering wheel towards the side you see more trailer helped me immensely today at school. Also, being someone who overcorrects, the instructor we had today told me to hold the steering wheel in both hands and put my elbows into my ribs and keep them there lol... it worked. No overcorrecting and perfect straightline backing all afternoon.

The instructor we had the last time had us using 1 hand at the top of the wheel and said to make small corrections, but offered no tips for me to solve my overcorrecting tendencies. With that one hand method I had way too much room to oversteer lol.