Autopilot keeps slowing down in same area on I-5 (Orange County to LA).

[JetFalcon]

On my commute from Orange County to Los Angeles on Interstate 5, autopilot constantly keeps wanting to slow down from freeway speeds to 45 mph like it thinks it is on local streets. It slows down drastically, to the point that I must cancel autopilot or risk slowing down to the point of getting rear ended, it's like someone stepping on the brakes for no reason. It's always in the same area too, like the border of Orange County & Los Angeles / 5 freeway. I believe the freeway was widened which causes the autopilot to think it's on local roads. And the GPS hasn't done anything to accommodate this new change.

It usually happens around this area where the Double Tree & AMC off the freeway.

 

[Crew Dragon]

I came to the forum with a similar question/problem. I have it happen on a section of road here in Ohio and was hoping to find some answers or even an explanation. In this spot (under a large, overhead sign), the speed will drop and it will actually change my cruise control speed to 55 from the 65 where I set it earlier!
I see a lot of threads on phantom breaking, but not this specific issue.

 

[EVEnergy]

There are mapping errors in the nav database which can cause the slow downs. It happens a lot less now than in the past (there are a few areas where I drive and get the same thing).

 

[1_Erik_21]

i don't think it's that much of a problem

 

[jkdman123]

i don't think it's that much of a problem

It is a problem and it’s gotten worse in SoCal. There are now at least 3 or 4 areas on various highways where autopilot will automatically reduce speed without warning for no good reason. I just discovered on on a major interstate that dragged me to 55 mph when the speed limit is 65. It’s dangerous, it’s getting worse, and it needs to be fixed.

 

[Dewg]

It is a problem and it’s gotten worse in SoCal. There are now at least 3 or 4 areas on various highways where autopilot will automatically reduce speed without warning for no good reason. I just discovered on on a major interstate that dragged me to 55 mph when the speed limit is 65. It’s dangerous, it’s getting worse, and it needs to be fixed.

There's always a reason. It's just a matter of finding it. Sometimes it's a truck 55 sign that gets misread, or a GPS error that puts the car off the freeway onto a side street, or the lanes shifted due to construction so the car thinks it's somewhere off the freeway, etc. The 405 freeway is getting widened for the past few years and it's difficult navigating through North Orange County without keeping a sharp eye on the speed and being prepared to toggle up the speed, or just driving manually.

 

[jkdman123]

There's always a reason. It's just a matter of finding it. Sometimes it's a truck 55 sign that gets misread, or a GPS error that puts the car off the freeway onto a side street, or the lanes shifted due to construction so the car thinks it's somewhere off the freeway, etc. The 405 freeway is getting widened for the past few years and it's difficult navigating through North Orange County without keeping a sharp eye on the speed and being prepared to toggle up the speed, or just driving manually.

As much as I paid for Autopilot (and it's more than 3X now than what I paid), those excuses don't go very far. Tesla has made tons of hay out of being first and innovating a lot, but I feel like they're just barely maintaining and all Elon cares about is just getting cars out the door instead of addressing problems that if they go unfixed will allow other companies to gain lots of ground eventually.

 

[thesmokingman]

That's not that bad. On the 405S near South Coast Plaze, the lazy Caltrans drew the tempory lanes thru that area zig zag unnaturally so its really hard for the car to centered in the lane. It's really obnoxious. And the one of the on ramp they made so screwed up that it is so narrow it freaks the car out. I have the beta viusualization on but rarely use FSD and when I went thru the 405 Fairview to 405S connector and went thru that sharp and tight connector, the car freaked and FSD visualizations stopped working.

 

[jkdman123]

That's not that bad. On the 405S near South Coast Plaze, the lazy Caltrans drew the tempory lanes thru that area zig zag unnaturally so its really hard for the car to centered in the lane. It's really obnoxious. And the one of the on ramp they made so screwed up that it is so narrow it freaks the car out. I have the beta viusualization on but rarely use FSD and when I went thru the 405 Fairview to 405S connector and went thru that sharp and tight connector, the car freaked and FSD visualizations stopped working.

The logic the car uses to stay in the lane is problematic. I can't imagine why they haven't fixed it yet. It seems like the car wants to always be in the middle of whatever lane lines there are. The only problem with this is that if you're in the far right lane on a highway and come up on an on ramp or an off ramp, the right lane line starts to diverge (or converge in an on ramp). The car sees this as an overall wider lane and will maneuver itself to the right to keep it in the 'middle'. But this makes you look like you're drunk and slightly weaving, as well as being generally disconcerting because it's unexpected behavior.

They should have it weighted toward the left lane line. If you just keep the car, say, 24 inches from the left lane line and reduce the push to be in the very middle of the lane then it would be a much more stable driving experience.

 

[Dewg]

As much as I paid for Autopilot (and it's more than 3X now than what I paid), those excuses don't go very far. Tesla has made tons of hay out of being first and innovating a lot, but I feel like they're just barely maintaining and all Elon cares about is just getting cars out the door instead of addressing problems that if they go unfixed will allow other companies to gain lots of ground eventually.

My bad, I see you just wanted to vent, so I'll let you continue undisturbed.

 

[gaswalla]

this is a significant issue - autopilot slows down suddenly, including using the brakes to go from 75 to 45... a car going with the flow of traffic would easily rear end the Tesla. On this stretch noted by OP, the freeway was recently widened and rerouted... Nav / Autopilot detect the freeway as a city road and thus suddenly hits the brakes

 

[Dewg]

this is a significant issue - autopilot slows down suddenly, including using the brakes to go from 75 to 45... a car going with the flow of traffic would easily rear end the Tesla. On this stretch noted by OP, the freeway was recently widened and rerouted... Nav / Autopilot detect the freeway as a city road and thus suddenly hits the brakes

Correct. The freeway is still under heavy construction with lane shifting off the current maps. It's the same as those with bad GPS hardware, where the car thinks it's in a different location than it really is, which can cause significant problems for all ADAS functions. Driver Assist and all navigation functions rely on accurate map coordinates. There are a few solutions: 1) Don't use Driver Assist in heavy construction areas - simply disengage and re-reengage after the construction zone. 2) When driving thru construction zones, keep a sharp eye on the speed limit, especially in areas where lanes are shifting. Be prepared to wheel up the speed if it should drop. 3) In areas where the lanes are shifting to the right, try to keep as far to the left as possible (including the carpool lane if you have access) to ensure GPS shows you still on the freeway - keep an eye on the map to make sure your arrow is showing on the freeway.