Model S characteristics when passing a semi trailer.

[ZEK7717]

As the new owner of a Model P100, I have experienced 3 episodes of my Tesla not responding to a semitrailer as it drifted towards the centerline as I passed it on the interstate. When the distance approached a foot, I was forced to override the autopilot for fear of contact with the truck. Are Tesla’s programmed to respond to these situations?

 

[Shateam]

Common complaint here on the forum. It’s referred to by some as “truck lust”

 

[ewoodrick]

A foot means that you can reach out and touch the truck. A foot also would mean that the truck as not approaching the centerline, but that it had gone significant over.
The car is going to stay in the middle of the lane unless it is actively trying to avoid something. Most drivers, tend to shy away from trucks and move away from them. This is actually a dangerous behavior, because they have decreased the margin on the other side of the car.
I had a car recently that was passing a truck in this same situation, but was so hesitant about being close to the truck that they went over the lane to the left of them.
The Model S is 7.2 feet wide, the average interstate lane is 12 feet, although some roads may get down to 10 feet. At that point, the Model S, between the lines will have 1.4 feet on either side.

 

[RDoc]

A foot means that you can reach out and touch the truck. A foot also would mean that the truck as not approaching the centerline, but that it had gone significant over.
The car is going to stay in the middle of the lane unless it is actively trying to avoid something. Most drivers, tend to shy away from trucks and move away from them. This is actually a dangerous behavior, because they have decreased the margin on the other side of the car.
I had a car recently that was passing a truck in this same situation, but was so hesitant about being close to the truck that they went over the lane to the left of them.
The Model S is 7.2 feet wide, the average interstate lane is 12 feet, although some roads may get down to 10 feet. At that point, the Model S, between the lines will have 1.4 feet on either side.

The car does not always stay in the middle of the lane. That is what the problem is and it has nothing to do with trying to avoid something. Many people, myself included have seen this behavior, although it's better now than a few years ago. Especially after changing lanes to the one next to the truck. The car occasionally will slowly drift right towards the truck. You can even see it in the lane display.

As I said, this has gotten better, but it is a real problem.

 

[Brettski]

More often than not I feel forced to break out of auto steer when passing a large truck. It may very well be my perception, but it simply feels unsafe - it’s that simple. Others in the car have expressed the same feeling that it gets “too close”.

Fortunately, this seems to be incrementally improving.

 

[quickstrike12]

I contend that part of the problem is the big truck creates a “low pressure” area around it aerodynamically with the wind coming off the front and speeding up along its sides. Essentially I think the car car can get into this area and get “pulled” towards the large truck.
This is why it always seems like you drift towards the truck. Since last few updates I feel like they have compensated for this behavior somewhat and my car “resists” this to some degree and it’s not as bad.
It’s very natural for a human driver to give a big truck a “large berth” when passing or being passed, but the Autopilot is is just lane keeping.

I for one take a good firm grip on wheel when alongside and prepare for any weirdness. Then relax after passing.
Never a good idea to ride alongside for any extended length of time in ANY car. Big truck tires explode on occasion and you don’t want to be there when it does.

My 2 cents.