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Tesla autopilot confused on mountain freeway

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Sacramento

2021 Tesla Model Y LR AWD
Mar 13, 2021
62
108
Sacramento, CA
I've taken a couple of trips in my two-month-old Tesla Y between Sacramento and Lake Tahoe on Interstate 80 and have experienced consistent problems with autopilot becoming confused by faded or non-existent lane markings and fog lines. Autopilot is pretty reliable until the car gets above the snow line and the stripes become inconsistent. The first time this happened I blamed poor visibility, but the weather today wasn't bad at all.

A couple of times today when the fog line disappeared, my Tesla drifted onto the right shoulder and was alarmingly close to the snow bank at 65 mph with no warning. I was tempted to see how far it would go on the shoulder before it recognized the error, but good sense overcame my curiosity.

A different incident was even more disturbing. I was in the right lane with a pickup truck coming up on the left when without warning the Tesla began changing lanes into the path of the truck. I grabbed the wheel and pulled the car back into the right lane. I suspect the car would have somehow avoided crashing into the truck, but my biggest concern is how the driver of the pickup might have reacted to my car suddenly encroaching in his lane.

I put video of two of the incidents on YouTube. They don't look as dramatic on video as they felt in the car, but this autopilot behavior is worrisome. I would expect the car to recognize its limitations and cancel autopilot when highway striping becomes unreliable. I suppose none of this is breaking news to Tesla owners who live in areas where the highways are not well maintained.

 
  • Informative
Reactions: pilotSteve
I wouldn't use / trust the current AP when lines are missing / faded / covered (by snow). In your first case, only the median line was visible, but the shoulder line disappeared. Unfortunately, Tesla doesn't provide a good tutorial to understand when current AP has issues / fails, so you have to learn by experience. Basically, you can trust AP to mostly work well in a straight line when the lines are clear, you're following a car, and no traffic merging (all 3 conditions). In any other case, there will be issues from time to time.
 
You could have shorted this to: another example of AP's merge lane drift. The "lane" gets wide and AP seemingly tries to drive right down the middle.

I've had AP try to follow the car ahead of me going into the left hand turn lane instead of going straight.

I've taken a couple of trips in my two-month-old Tesla Y between Sacramento and Lake Tahoe on Interstate 80 and have experienced consistent problems with autopilot becoming confused by faded or non-existent lane markings and fog lines. Autopilot is pretty reliable until the car gets above the snow line and the stripes become inconsistent. The first time this happened I blamed poor visibility, but the weather today wasn't bad at all.

A couple of times today when the fog line disappeared, my Tesla drifted onto the right shoulder and was alarmingly close to the snow bank at 65 mph with no warning. I was tempted to see how far it would go on the shoulder before it recognized the error, but good sense overcame my curiosity.

A different incident was even more disturbing. I was in the right lane with a pickup truck coming up on the left when without warning the Tesla began changing lanes into the path of the truck. I grabbed the wheel and pulled the car back into the right lane. I suspect the car would have somehow avoided crashing into the truck, but my biggest concern is how the driver of the pickup might have reacted to my car suddenly encroaching in his lane.

I put video of two of the incidents on YouTube. They don't look as dramatic on video as they felt in the car, but this autopilot behavior is worrisome. I would expect the car to recognize its limitations and cancel autopilot when highway striping becomes unreliable. I suppose none of this is breaking news to Tesla owners who live in areas where the highways are not well maintained.