Cars tailgating whilst on Autopilot

[joninmelbourne]

I'm really loving my Tesla, one month in I can't see ever going back to an ice car.

Driving home tonight in heavy traffic on Autopilot I had a couple of cars nearly go into the back of me. I find whilst on Autopilot and in a traffic jam the car accelerates quite hard when there is a gap in the traffic and puts on the brakes quite hard when approaching a stopped car, and then stopping about a metre short from the stopped car in front. One van behind me was driving close and didn't expect the hard braking and stopping a metre back and I saw him almost hit me and he sounded his horn as if I'd slammed on the brakes too late.

5km down the road it happened again with another car nearly going into the back. Car was on Autopilot with one car length following distance (the minimum). Anybody had a similar experience? Cheers

 

[lklundin]

One van behind me was driving close and didn't expect the hard braking and stopping a metre back and I saw him almost hit me and he sounded his horn as if I'd slammed on the brakes too late.

If a vehicle behind you has a problem with your braking, then its driver is at fault for not maintaining proper distance.

Can the Tesla rear camera record what it sees?

 

[Mark E]

Technically its their issue if they are driving too close, but personally I have the distance set on 7 (max) as its much more pleasant, and about the distance that I'd leave anyway if I were driving.

While you may be in the right legally a car hitting you from behind is somewhat inconvenient as your car will be off the road being repaired, and they may even push you into the car in front doing even more damage.

 

[Aieukl378]

What I notice while on Autopilot is how bad/terrible other drivers are. As my Tesla is sure and steady on AP other vehicles are weaving in and out, stopping short etc. all around me. Cars ahead of me aren't a problem as AP adjusts to them but as the OP notes vehicles behind are a issue(unless it's a Tesla w/AP of course.

 

[Brian May]

If you get killed because a truck crashes into the back of you, it doesn't matter who is at fault - you are still dead.

Coroner finds no evidence Volkswagen Golf lost power in fatal crash

In fact there doesn't seem to be any mention that maybe the truck driver was at fault in this accident - was the truck tailgating at the time? Would seem likely, otherwise he wouldn't have hit the car in front of him - even if it did stop suddenly - for any number of possible reasons.

 

[MP3Mike]

Car was on Autopilot with one car length following distance

That setting is not a car length setting, it is a time based setting. (How far the car will travel over a period of time.) So the faster you go the more distance a given setting will provide.

What firmware version are you on? (People have mentioned that the TACC in 8.x is much smoother/more natural than in 7.x) Though I suspect part of the problem is having TACC set to 1.

 

[Shock-On-T]

The problem is that you're in Melbourne
Over the past few years on half a dozen occasions I've driven down and spent a week working there, and each time noticed a difference in "driving culture" compared to Sydney.
It feels generally more aggressive, and I see a lot more red lights run, speeding, weaving at high speed on freeways etc.

Your concern about autopilot is valid. It tends to brake earlier and harder than a human driver, and leaves a bit more of a gap during the deceleration phase. Once deceleration is almost complete it does close the gap to a more 'normal' distance.

If you have some knuckle-dragger trying to stay 200 milliseconds behind you then he will keep getting surprised (then annoyed) at your perceived over-braking. Setting the chase length/time to a higher value (I like 5) will soften all these attributes, but you can't please everybody, and van-man would probably find some other reason to be annoyed.

How about getting some Yosemite Sam "Back Off!" mudflaps?

 

[garyjac]

It seems to me that the "issue" is one of human muscles, versus machine tirelessness. Granted there will always be imbeciles who have to be "opp ars" as it were, just in case they get where they're going 20 secs later than anyone else; but, aside from those, the continuous effort of trying to keep the car at constant speed and under a certain speed (limit) all the time does tire the muscles. Also, ICE car engines and the associated gear boxes are really only "happy" in each gear in a narrow speed range and that range does not necessarily match the speed limit. Hence, human drivers in ICE cars tend to frequently be above and below(?) the speed limit because they are gradually, imperceptibly tiring and need to constantly adjust the pedal to keep their machine happy.

 

[omniwolf]

something else to consider - when using TACC or AP, the brake lights don't turn on immediately. The Tesla will begin slowing down using the regen brakes first, and (usually) only a bit later will brake lights turn on (either when TACC decides regen isn't enough and friction brakes are required, or in some (most) cases, a high amount of regen will turn on the brake lights). If the person behind you isn't paying attention, they might not notice you slowing down until later in the piece, etc etc.

But really, having the following distance set to 1 is too small in my opinion. I have it set to 1 if i'm drafting behind a friend on a road trip or something and they're aware of what I'm doing, but otherwise i usually have it at 3.

 

[raynewman]

something else to consider - when using TACC or AP, the brake lights don't turn on immediately. The Tesla will begin slowing down using the regen brakes first, and (usually) only a bit later will brake lights turn on (either when TACC decides regen isn't enough and friction brakes are required, or in some (most) cases, a high amount of regen will turn on the brake lights). If the person behind you isn't paying attention, they might not notice you slowing down until later in the piece, etc etc.

But really, having the following distance set to 1 is too small in my opinion. I have it set to 1 if i'm drafting behind a friend on a road trip or something and they're aware of what I'm doing, but otherwise i usually have it at 3.

The brake lights come on immediately the car starts to slow. Put simply, the lights are not connected to the brakes.

 

[MP3Mike]

something else to consider - when using TACC or AP, the brake lights don't turn on immediately. The Tesla will begin slowing down using the regen brakes first, and (usually) only a bit later will brake lights turn on (either when TACC decides regen isn't enough and friction brakes are required, or in some (most) cases, a high amount of regen will turn on the brake lights).

That is all exactly the same as if you were driving the car manually. Or for that matter driving any car, if you slow down by easing up on the accelerator the brake lights don't come on. There is nothing special in this regard to TACC/AP.

 

[raynewman]

That is all exactly the same as if you were driving the car manually. Or for that matter driving any car, if you slow down by easing up on the accelerator the brake lights don't come on. There is nothing special in this regard to TACC/AP.

Except in the Model S where the brake lights come on immediately it starts to slow.

 

[MP3Mike]

Except in the Model S where the brake lights come on immediately it starts to slow.

No, only when it starts to significantly slow. (If you have the regen set to low you are less likely to cause the break lights to come on, or if you only let up on the accelerator a little bit.)

 

[immolated]

"1" following distance is too close for smooth slowing. 3-4 is decent, 7 is very gentle.

 

[raynewman]

No, only when it starts to significantly slow. (If you have the regen set to low you are less likely to cause the break lights to come on, or if you only let up on the accelerator a little bit.)

No one in their right mind sets regen to low.

 

[EVCollies]

On my daily commute, the "passing" lane is really the "tailgate" lane. Even if you are passing someone, if you are not tailgating, the guy behind you gets angry. I just stay in the "slow" lane and am never far behind the racers in the left lane when I see them at the next light.

 

[garyjac]

This TG business and rushing to get to the next light was worked out years ago, by traffic engineers. If you spurt around and fart in and out, you arrive 25 to 40 SECONDS ahead of someone who observes all the courtesies and rules of the road. The traffic light system regulates!

 

[Brian May]

It seems to me that the "issue" is one of human muscles, versus machine tirelessness. Granted there will always be imbeciles who have to be "opp ars" as it were, just in case they get where they're going 20 secs later than anyone else; but, aside from those, the continuous effort of trying to keep the car at constant speed and under a certain speed (limit) all the time does tire the muscles. Also, ICE car engines and the associated gear boxes are really only "happy" in each gear in a narrow speed range and that range does not necessarily match the speed limit. Hence, human drivers in ICE cars tend to frequently be above and below(?) the speed limit because they are gradually, imperceptibly tiring and need to constantly adjust the pedal to keep their machine happy.

I find I have to watch my speed very carefully when manually driving the Tesla. i.e. I set the speed to the speed limit, maintain steady foot pressure, look at the road, and look back down and suddenly find I am doing 10km/h over. Oops. Wonder if this is the hilly environment I live on.

Setting the car to chime if it goes over the speed limit helps, although it has some quirks at times reading speed limits signs. Especially around school zones. Road works within school zones don't work particularly well either. Does the car understand school hours for school speed limits, or is this coincidence?

You can have the car only chime if you go +X km/h above the speed limit - which is good. Unfortunately the same offset is also used by the autopilot :-(

 

[Shock-On-T]

I find I have to watch my speed very carefully when manually driving the Tesla. i.e. I set the speed to the speed limit, maintain steady foot pressure, look at the road, and look back down and suddenly find I am doing 10km/h over. Oops. Wonder if this is the hilly environment I live on.

Setting the car to chime if it goes over the speed limit helps, although it has some quirks at times reading speed limits signs. Especially around school zones. Road works within school zones don't work particularly well either. Does the car understand school hours for school speed limits, or is this coincidence?

You can have the car only chime if you go +X km/h above the speed limit - which is good. Unfortunately the same offset is also used by the autopilot :-(

It definitely gets confused with school zones, road works, and quite a few other places.
I've found the TACC to be very helpful in keeping to the speed limit. Works well on roads I wouldn't use autopilot (too winding, narrow). Plus it has better reaction time than me...

 

[BenT]

Haters gonna hate and tailgaters gonna tailgate. It's nothing to do with AP. Other drivers are the problem. On the open road I just set my speed on AP and try not to look too much in the rear view. Bob keeps a constant speed at the speed limit which must be very frustrating for those other drivers who want to sit on my tail.