Concerned about rear collision when car slows on its own

[stonelance]

I do worry about the phantom braking at highway speeds, and a little about the abrupt braking in stop and go. I also have had the emergency braking kick on a couple of times that I'm pretty sure it was absolutely required and it caused the car to stop much farther away than I would have, and worries me about the person behind not having the space to stop, but I would have that concern even if I was in a car that didn't have the emergency braking. I just wish the follow distance setting also had a separate setting to control how tightly to maintain that distance. It would probably be good for efficiency to be less aggressive with braking and acceleration.

Is there any information on what each follow setting does at each speed?

 

[stevevets]

Every time I'm on autopilot and a car way off in the distance makes a left turn that crosses my lane, my car slams on its brakes. While it's true that technically all drivers should drive 100% perfectly and assume that every car in front of you is going to brake check you, it's also true that it's absolutely insane to expect that that will be the case in reality. So Tesla should fix this, and those who think Tesla is infallible and everyone else should just drive better should stop.

 

[DopeGhoti]

Every time I'm on autopilot and a car way off in the distance makes a left turn that crosses my lane, my car slams on its brakes. [...] So Tesla should fix this

If Autopilot were supposed to be used on streets where it's possible for cars to make a left in front of you, yes, they should. But it is not.

That said, what I usually do (because I also use Autopilot inappropriately) is set my follow distance to 3 on surface roads, and 6 on the highway. Then someone turning across my lane is much less likely to make my car preemptively brake. The other thing you can so, since you should be paying attention and seeing this coming anyhow, is put your foot on the accelerator and just drive through the moment where the car would start to brake. But then if that car stops in your lane, you'll have to remove said foot or you'll have a sad time.

 

[Ivan Abundance]

Get in the habit of cruising the local strip mall in the evening about every two weeks, and do a slow circle so your can check all your lights in the window reflections. Not to be confused with a stripper maul.

 

[Joshan]

I had my son-in-law drive behind me for an hour on Saturday night and I used AP/FSD the entire time. (we were returning from a family gathering and he lives in another state so wanted to follow me) I wanted to get feedback on what it is like following a Tesla for a long period of time on many different roads. It was about 50% highway and about 50% local roads. The only thing I did was make turns and stop at red lights and stop signs (if no car in front of me).

When we got back to my house and I asked him, he had no idea that I was on Auto Pilot. He stated he noticed nothing unusual or different than following any other car.

 

[Gava71]

I do worry about the phantom braking at highway speeds, and a little about the abrupt braking in stop and go. I also have had the emergency braking kick on a couple of times that I'm pretty sure it was absolutely required and it caused the car to stop much farther away than I would have, and worries me about the person behind not having the space to stop, but I would have that concern even if I was in a car that didn't have the emergency braking. I just wish the follow distance setting also had a separate setting to control how tightly to maintain that distance. It would probably be good for efficiency to be less aggressive with braking and acceleration.

Is there any information on what each follow setting does at each speed?

Re Phantom breaking on the highway, I believe it’s due to the maps, I’ve noticed that there are specific spots in my commute where this happens and I correct at those spots. But also I can see that the speed limit warning goes from 65 to 40 in a second and the car slams the brake and then it goes back to 65 but the car doesn’t react that quickly, or even dismiss the blip. Google maps should be fixed for those errors in speed limits inconsistencies AND Tesla should have some AI to know it was a blip and dismiss it.

 

[Joshan]

Re Phantom breaking on the highway, I believe it’s due to the maps, I’ve noticed that there are specific spots in my commute where this happens and I correct at those spots. But also I can see that the speed limit warning goes from 65 to 40 in a second and the car slams the brake and then it goes back to 65 but the car doesn’t react that quickly, or even dismiss the blip. Google maps should be fixed for those errors in speed limits inconsistencies AND Tesla should have some AI to know it was a blip and dismiss it.

Agree completely with your assessment and it is also my experience. But I believe you may have listed the wrong site for corrections. I believe this is the correct site.

www.openstreetmap.org

My understanding is speed limit sign recognition will also return when HW3 is mass rolled out as it has the capacity to handle the additional load.

 

[pebkac]

The break lights come on, and you get used to using the timing of the one pedal..

 

[Runt8]

Agree completely with your assessment and it is also my experience. But I believe you may have listed the wrong site for corrections. I believe this is the correct site.

www.openstreetmap.org

My understanding is speed limit sign recognition will also return when HW3 is mass rolled out as it has the capacity to handle the additional load.

The current consensus seems to be that OSM is only used for smart summon. Someone please correct me if anyone has found evidence of OSM being used for navigation or autopilot.

 

[Nocturnal]

I think AP brakes later than I'd like, not too early.

My point is that a car that slows/brakes abruptly is more likely to get rear ended by a driver following too closely and/or not paying attention.

Our Tesla slows much more abruptly while on Autopilot in situations where cars "dive" into the gap in front of us.

Unfortunately, tailgating is common in So California...and at typical 70+ mph freeway speeds, it's safer to maintain a smoother pace than Autopilot accomplishes in the situation I described above. If possible, it's smart to change lanes away from tailgaters (as was mentioned earlier), but that's not always an option when traffic is heavy.

For this reason, we almost always prefer to have full control of the Model 3 on So California freeways.

Hope that helps.

BTW @Joshan...tailgaters abound in Chicagoland! It's as crazy there as in So California...sometimes I think even moreso.

Just have AP slowdown and deal that way, assuming you aren't just cruising in the fast lane.

 

[tvad]

Just have AP slowdown and deal that way, assuming you aren't just cruising in the fast lane.

I don't understand how your comment pertains to our experience of abrupt braking in the situation I described.

 

[DopeGhoti]

I think AP brakes later than I'd like, not too early.

I can concur with this. I've gotten used to TACC braking in a manner that I'd consider late for stopped traffic ahead, but I have a long history of tending to coast to a stop when able.

 

[Nocturnal]

I don't understand how your comment pertains to our experience of abrupt braking in the situation I described.

I was responding to your issues with tailgating.

 

[Joshan]

The current consensus seems to be that OSM is only used for smart summon. Someone please correct me if anyone has found evidence of OSM being used for navigation or autopilot.

Please do correct me if wrong, as I am not 100% sure. I believe I read that on this forum when asking about how to correct an incorrect speed limit near my house. Could be coincidence but about 2 weeks later the speed limit was correct.

Be very good to know with 100% certainty.

 

[Runt8]

Please do correct me if wrong, as I am not 100% sure. I believe I read that on this forum when asking about how to correct an incorrect speed limit near my house. Could be coincidence but about 2 weeks later the speed limit was correct.

Be very good to know with 100% certainty.

I've seen several posts with people saying they've corrected the speed limit in OSM and saw no change. Your post is the first I've seen where it may have had an effect. I would love to be able to correct speed limits - in my area other than highways and major streets they're almost always incorrect.

 

[follow.johnny]

I always drive with the rear view camera up and always monitor the car behind me when slowing down both with autopilot turned on or manual driving.

Also driving defensively to leave myself a lot of room in front just in case a car is going to rear end me I can move up and avoid or reduce the impact.

 

[tvad]

I was responding to your issues with tailgating.

I understand. Please explain your comment and how it would solve our problem.

 

[Knightshade]

I've seen several posts with people saying they've corrected the speed limit in OSM and saw no change. Your post is the first I've seen where it may have had an effect. I would love to be able to correct speed limits - in my area other than highways and major streets they're almost always incorrect.

FWIW on a road I drive every day near my house it says 55 the whole way in OSM.

According to the car though it's 55 for part of it- and "I have no idea so will restrict you to 45" the rest of it.

So wherever it's getting speed limits from, it's not OSM.

 

[Nocturnal]

I understand. Please explain your comment and how it would solve our problem.

No tailgating = no problem

 

[tvad]

No tailgating = no problem

I cannot control tailgaters behind me, and neither can Tesla's AP, so I don't see the applicability of the solution you propose.

Thank you for your comment. Appreciated.