How far must you clear an obstacle in your rear view mirrors befor turning left or right?

Far enough so that your trailer AZZ doesn't HIT it!


Okay, that was kinda a cheap shot. We like to kid a bit here.

I don't think there is any set forumula. You just have to learn, or FEEL, where your trailer will "track." First thing is... don't "lean" into the turn with your tractor! IOW... steer WIDE with the tractor on ANY turn so that your tandems will have more room. Don't start your turn with your tractor just because you are "turning" in that direction. If possible, ALWAYS turn wide in the other direction with your tractor before making the turn.

But, if you insist on some type of measurement.... I'd say, HALF of your trailer should be "ahead" of the turn, and your tires should be half of THAT from the obstacle. IOW... think of a right triangle. If you want to drag your tandems around an obstacle on the "hypotenuse," you should have created a right triangle with your truck tandems.

Ah heck... this is difficult to explain. Keep your trailer about 6 feet away from the obstacle, drive STRAIGHT forward (or a bit left if you can) until at least half of your trailer (or the tandem length) are ahead of the obstacle, then make your turn. The right angle of your turn will allow the hypotenuse to clear the obstacle.

Whenever possible.... steer away from the obstacle, and away from it, until you absolutely HAVE to make the turn. Remember that, once you start your turn, the tandems my "sit down" and become a pivot point. So... get them beyond the obstacle... or as far away from them as possible.

Another way of looking at it is this: If you see where you want your truck to be as you pull out of the situation, make sure your tandems are at LEAST that far out before you start/finish the turn.

You CANNOT "cut corners" with a trailer.

No matter how wide you swing, IF your tandems are still behind or abreast of the obstacle, you will drag them right INTO it!

Now... I was assuming you were talking about truck stop parking/exiting. If you are talking about passing someone... well.... what's your hurry? Make sure you could put a HOUSE between you before pulling over in front of another truck!

Impossible to answer the way that the question is asked without giving the simple answer that was eluded to above... "Far enough that you don't hit anything with the trailer" is the answer.

If you have been not driving at all in a tractor-trailer (yet) the first time that you do.. the answers will kind of become obvious on the first few turns and you instructor (I hope) will explain the process of how these turns work. The first thing that MUST be removed from your mind is turning in arcs like in a car... you make round or "arced" turns in cars.. you make SQUARE turns in tractor trailers.... SQUARE! Using ALL the space that you have available and using the mirrors and landmarks to make the proper safe and legal turns (into the correct lane in multi-lane roads.

To make a right turn, you drive STRAIGHT into the intersection and then turn HARD to to pull your trailer OUT into the intersection as far as you can then AROUND the corner. As you turn to the right you aim fo the outside edge of the road and then drive STRAIGHT down that edge,, STRAIGHT being the key word.. as you drive STRAIGHT down the outside edge of the road, you are watching your right mirror at the trailer (for morons trying to get by you on the right and other stupid things) but mainly you are watching your trailer tandems.. you have to estimate where the CENTER of the corner is and when the trailer tandems reach this point. you THEN steer HARD towards the right.. if you do this correctly, there is absolutely no way that you can run over a curb! You square off every turn you pull the trailer OUT into the intersection.. you pull around the corner by driving straight down the outer edge of the road and then you PIVOT the trailer around the corner keeping the wheels close to the curb keeping people, cars, boats from being able to get inside of that turn.. more on left turns if I get a chance... gotta go do some work stuff...I used to have some diagrams.. but that was a couple of computers ago..