Flaky Auto Lane Change

[Haxster]

I just drove from Silicon Valley to Santa Barbara and back on 101 in my 17.17.4 AP2 MS. About 700 miles

I used autopilot most of the way and it worked very well.

Auto lane change was another matter. About 20% of the time, the car wouldn't change lanes. Speed, lane markings, straightness, and traffic conditions were all ideal for a safe lane change. But Sparky just stayed in its lane, oblivious to the blinking turn signal. Typically, a few miles later, the auto lane change would work.

Any idea what's going on?

 

[googleiscoul]

Was auto lane change available?

 

[MurrayJimW]

I have a separate issue with this. I have a 2 day old car and obviously am still learning quite a bit. Yesterday I took it out on the interstate for a little autopilot work. Autopilot is flaky in town (that's being kind), but works well enough on a large divided highway. I decided to try auto lane change and it worked great except there was a car in the lane I requested. The autopilot (and me) were completely unaware the vehicle was there until the obligatory horn honk and obscene gesture from the other driver. While I realize I screwed up here, I thought the autopilot would check to make sure the lane was clear before changing lanes. Am I mistaken or was this a failure of the sensors to pick up the other vehicle as I suspect? No attacks please. I realize clearing the lane is/was completely my responsibility and I'm not blaming the auto pilot for my mistake. I was just under the impression it would function at least as well as blind spot monitoring in a 2014 Ford we own. I was surprised when it did not.

 

[hitparader]

I've noticed almost an immediate jerk response to the signal indicator going on as well, then once halfway established, it grandpa merges the rest of the way.

 

[3s-a-charm]

I've also run into scenarios where the lane I want to get to is wide open and I hit the turn stalk only to stay in my lane without changing lanes. I'm thinking it's an AP2 bug that will be worked out via OTA update.

 

[Snowstorm]

If I recall correctly, AP2 auto lane change only works on roads Tesla considers divided highways. Perhaps the data base of that doesn't matches your own classsification leading to apparent inconsistent behaviour. My AP1 loaner lane change works anywhere.

 

[Haxster]

Was auto lane change available?

Yes. Just after one failure to auto change lanes, I actually checked to make sure that is was still enabled. It was. The divided highway that I was on was well marked and a prime fit for auto lane change.

And I checked to see if any of the cameras of sensors were blocked. They weren't.

Maybe the cure will be in the next update...

 

[googleiscoul]

Yes. Just after one failure to auto change lanes, I actually checked to make sure that is was still enabled. It was. The divided highway that I was on was well marked and a prime fit for auto lane change.

And I checked to see if any of the cameras of sensors were blocked. They weren't.

Maybe the cure will be in the next update...

Did you see the little faint lines to the left and right indicating you can change lanes?

 

[Haxster]

Did you see the little faint lines to the left and right indicating you can change lanes?

Not aware of those. Will look for them next time. Thanks!

 

[CameronB]

Have had my Model S for just over a week now. Have been using AP2 pretty extensively (and overall very pleased - not perfect but has been very good in my use so far).

I have not used auto lane change very much. Probably 5 times total. 4 times it worked great. Smooth, fast and "confident". The fifth (latest) attempt was completely different - I cleared the lane, signaled and the car did a "half jerk" to the right, crossing the lane divider by maybe a foot or two...then jerked back into the lane I had come from. Totally unexpected and odd. There were no nearby cars or objects in the (right) lane I was attempting to change lanes into so not sure why the car kind of decided to abort the lane change. Just my initial observations...I definitely plan to use this feature more soon and develop a better understanding of how well it works and any idiosyncrasies.

@Haxster Although I have always manually cleared the lane before doing auto lane change (as you attempted to do though probably you had someone in a blind spot), I would also assume that AP should be using it's ultrasonic sensors (and at some point in the future, side cameras) to help ensure that no vehicle is in the lane you are attempting to change into. I would guess (though admittedly don't know for sure) that Tesla intends for it to work like this - but like with all of this new tech, it doesn't always work perfectly. Logically it would need to be in order for Tesla to fulfill it's stated goal of having automation be better/safer than human drivers (ultimately). Humans and mirrors might occasionally fail to see a car when lane changing (it's rare, right? But it happens to all of us at least a couple of times during the decades we drive). But humans don't have 8 cameras, radar and 360º ultrasonic sensors...so with all of that tech at the car's disposal (yes, I know not all of that is active at this time, but bear with me), it definitely should be able to do a theoretically much better job changing lanes than us meatbags could. Emphaseis on theoretically.

 

[David29]

FWIW, AP1 also exhibits these behaviors some of the time. First, my AP1 car will occasionally fail to change lanes for no reason that I can see. When it does fail, I either try again or just change lanes manually. (I have learned that it will not change lanes below a certain speed. That minimum speed is 30 mph according to the manual, but sometimes seems to be higher than that.)

Second, the car can try to move into an adjacent lane when there is another vehicle closing fast in the adjacent lane. On AP1 vehicles, the outward detection range of the ultrasonics is reportedly only about 16 feet. So it can tell if the lane is empty right now, but even a slight difference in speed between lanes could result in the failure to detect an upcoming vehicle before it reaches the space your car thought was empty. So, yes, you must check the mirrors yourself and be sure the space not only is now empty but will be in a few seconds when the maneuver is underway. (AP2 has longer range ultrasonic sensors, as I understand it, but the point still applies. Keep an eye out for approaching vehicles that Ap might not detect in time.)

 

[Haxster]

@Haxster Although I have always manually cleared the lane before doing auto lane change (as you attempted to do though probably you had someone in a blind spot),

Actually, I was very careful to make sure that a manual lane change would be safe every time I tried an auto lane change (I don't trust it enough yet to do anything other than an extremely low risk change). No blind spot. No fast closing vehicle in the new lane, etc.

Another annoying anomaly I've noticed is that if you're relatively close behind a car in front (but not tailgating) before changing a lane, just after the lane change (or sometimes just before), the car senses the car in your old lane and slows down abruptly. This puts you at risk of being rear ended, honked at by the car behind you in your new lane, or tongue lashed by your passengers. Not good.

 

[MarcusMaximus]

Not aware of those. Will look for them next time. Thanks!

I'm going to guess that's what happened. I've seen a few times where, for whatever reason, those lane lines don't show up and the car doesn't respond to turning on the blinker(usually it's actually the other way around, with the car failing to react and then I see the lane adjacent lane lines are missing, but you get what I mean). Most recent time was actually just yesterday, where it looked to me like a shadow from the center divider was falling on the lane line and making the car not detect it as a lane, and, therefore, ineligible for merging into.

 

[googleiscoul]

I'm going to guess that's what happened. I've seen a few times where, for whatever reason, those lane lines don't show up and the car doesn't respond to turning on the blinker(usually it's actually the other way around, with the car failing to react and then I see the lane adjacent lane lines are missing, but you get what I mean). Most recent time was actually just yesterday, where it looked to me like a shadow from the center divider was falling on the lane line and making the car not detect it as a lane, and, therefore, ineligible for merging into.

It's that and also on some divided highways in fact autopilot does not have the auto lane change feature enabled.

 

[azmodls]

I just got the latest 17.24.48 update, and had a couple of times where it would not change even though it appeared to be wide open.