Welcome to Tesla Motors Club
Discuss Tesla's Model S, Model 3, Model X, Model Y, Cybertruck, Roadster and More.

Autopilot Lane Change


Being cyberbullied by TMC users PhilDavid + DCEV
Mar 30, 2019
Does anyone have insight as to what conditions are required for automatic lane changing to work? I only use autopilot with nav on autopilot engaged on freeways and somtimes the auto lane change feature works and sometimes it doesn't and I can't correlate with conditions.

Work as in?
It interrupted a lane change in progress (started, then returned)?
It never did/offered a lane change, even though it seems like it should have (or had done before)?

Other than the NoA settings available, with the new update and visualization in the instrument cluster, I've seen that the lane detection is where it has gone bad for me.

It will only perform or suggest the change as long as it detects a lane is changeable (dashed paint). However, I've seen it where it will (in the visualization), become solid temporarily, even though it shouldn't. If it's in the middle of a change, or suggesting, it stops and returns to continue on in the lane it was in.

But, not sure what you've seen?
I guess I wasn't very clear.

In normal operation if I come up behind another car a I get a message to the effect that a lane change to a faster lane is about to be made, the blinker comes on and, if the faster lane is clear, we move over to that lane. At other times under what seems to be identical circumstances when coming up on slower traffic it just slows down to prevent rear ending the car in front. No lane change takes place.

When clear of the slower traffic under normal circumstances the annuciator will announce that it is going to leave the passing lane, the blinker comes on and the change is executed. But sometimes that never happens and if faster still traffic is approaching it is necessary to manually operate the turn signal to effect the transition back to the right hand lane.


Being cyberbullied by TMC users PhilDavid + DCEV
Mar 30, 2019
All, I've encountered that (same situation, or even same place, but different actions) and I've now watched the IC and have seen the lane representation change from dashed to solid. It won't cross at all of it shows solid (uncrossable lane). Are you sure that's not happening to you?

Have you checked the visualization in the IC to see if there was an issue with the lane detection?
Here is a difference between detecting a lane (solid blue line), and detecting a lane that can be changed into (dashed blue line).

Autopilot is pretty good at detection a lane (solid blue line), it has to do even more work to detect a lane that can be changed into (dashed blue line)

I believe autopilot is going to error on the side of caution and if there is any question the line is not dashed autopilot will not execute a lane change -- meaning, on any stretch of road were the lane markers are not clearly being picked up by autopilot, do not expect autopilot to execute a lane change.
My biggest gripe with the auto lane change is that I can't seem to find a way for it to actually be automatic. I'll be driving with NoA, the MCU will tell me it's going to change lanes, puts the blinker on, but it insists on me having my hand on the wheel basically nudging the car into the lane it's going to change to. It kind of defeats the purpose.

For now, I turned off the automatic speed-based lane changes because I would rather just half-press the directional stalk to initiate a suggested change vs. having to actually torque the wheel to get the change to happen.
After some experimentation with this (mine never once changed lanes automatically) I just touch the turn signal to go around the slow guys .
I regularly drive 200 miles mostly freeway to our summer home and it has never worked "as advertised "...Someday perhaps .
Most fun car I have ever had ...

About Us

Formed in 2006, Tesla Motors Club (TMC) was the first independent online Tesla community. Today it remains the largest and most dynamic community of Tesla enthusiasts. Learn more.

Do you value your experience at TMC? Consider becoming a Supporting Member of Tesla Motors Club. As a thank you for your contribution, you'll get nearly no ads in the Community and Groups sections. Additional perks are available depending on the level of contribution. Please visit the Account Upgrades page for more details.