Almost Got Hit While on Autopilot Today

[wdolson]

Are you saying that Automatic Emergency Braking kicked in (you would see the notification on the IC and you'll here a chime) or was this just the TACC component reacting to the slowing/stopped car in front of you?

I don't know what the instruments were trying to tell me. I was too busy assessing the situation outside the car to pay much attention to what was going on inside. As I said, I did think the car braked harder than I would have in that situation, but I can also see more car lengths ahead than AP can.

I try to balance how close to get to the car in front while leaving as much stopping distance as possible for cars behind me.

I'd prefer too much space to too little in a panic stop situation. Don't forget, AP doesn't know why the guy ahead is stopping so suddenly... he might be about to pile into the back end of a semi. If that happened, his hard deceleration would become a dead stop about the length of his crumple zone. Assuming the car ahead is going to continue braking at the same rate and matching that with AP would be dangerous - better to leave some space in case he slows faster than you can.

Yup. Unless you're behind a big truck, a human can usually see something around the vehicle ahead, but while I've seen more than one ghost car appear on the car's screen, AP is primarily only concerned with the car immediately ahead. The current AP is very limited in its data collection ability, but with the new three camera setup on the leaked schematics, it should be able to monitor what's going on with all the cars ahead and might make better decisions.

There's another practical reason for stopping a bit back from the car in front in a situation like this. All too often, if you do get rear ended by the Mustang, you might get pushed into the car in front of you. Then it becomes an argument about who hit whom, when. But if the front of your car is untouched, responsibility is obvious, even to the insurance company.

I was in one of those kinds of accidents once. It was while visiting Portland when I lived in Seattle. I was on a curving freeway transition (I-5 to I-84) and traffic stopped halfway around. I was looking ahead trying to see if the stoppage was just slow traffic, nearby accident or what when an uninsured driver hit me. The force of the impact threw my foot off the brake and pushed me into the car in front.

I was driving a rental because my car was in the body shop from another accident a couple of weeks before. I learned that day about Ford's Ralph Nader switch. The fuel pump shuts off in a rear ender accident and needs to be reset by pushing a button inside the trunk. I was unaware of it and the car wouldn't move. Some of us pushed it to the side and someone familiar with Fords told me about it. We managed to get the trunk open, but the switch was moved in the accident. It was behind a structural piece and I could just barely get my finger on it. The car ran fine after that, though it was crunched on both ends.

As a replacement Hertz gave me a Thunderbird, which was fun to drive. Hertz kept going after me for the money for over a year, and I kept redirecting them to the guy responsible and my own insurance company, and they finally got the message and left me alone, but I had to deal with them talking about sending me to collections.

But that's probably one of those stories for ICE Cars are Dangerous.

 

[beeeerock]

I've been doing a lot of driving this week on a large, fairly high speed road (3 lanes each way, big median, 45-55MPH speed limit) with stoplights. Autopilot is doing most of the driving and is doing a great job of reducing my stress and rage level, but it really doesn't handle stopped traffic very well. I tend to be slightly slower than the flow (I'm only willing to go 5MPH over the limit) so what tends to happen is we all bunch together at a stoplight, then we get moving and the other cars pull ahead a bit, then they reach the next red light and I approach them and Autopilot waits way too long to start slowing down. I usually disengage it in advance when this happens and handle my own slowdown, because it's just a lot more comfortable. I don't know just how far out it can reliably see, but if it can see sufficiently far, then it would be great if it could start braking earlier and less.

I think it's important to understand that AP isn't necessarily going to detect vehicles far up ahead that haven't yet locked into the radar system. If it's aware of cars ahead and they slow down, it will reliably slow you down. But depending on it seeing a car already stopped as you approach at 55 mph... that's not something I'd count on. It likely will, but I'd say it's then more about accident avoidance than a TACC speed adjustment and casual stop.

 

[RogerHScott]

AP so far, it seems to wait longer than I would to apply the brakes (to the point where I'm considering hitting them myself), then has to apply them much harder than I would as a result. In traffic, I would say gradual is much better than abrupt just about every time.

This seems like something it would be easy enough to make adjustable -- within limits of safety, of course.

 

[RogerHScott]

I don't know just how far out it can reliably see

Well, you actually do know a lower bound on this: the point at which a car show up in front of you on the display.
My impression is that's pretty far out there.

 

[RogerHScott]

Then it becomes an argument about who hit whom

Having been the rear-most car in exactly this situation (many, many years ago), I can tell you there was no argument whatsoever.
I was totally, completely at fault. Tailgating laws are generally very simple and clear.

 

[wdolson]

Unless there is compelling evidence to the contrary, the rear-most car is at fault.

My SO's law partner had a rare case where the rear-most car wasn't at fault, but it took dash cam footage to prove it. The guy in front was a road rager, who pulled in front of the car with the dash cam and then immediately slammed on the brakes causing the accident. The car in front then took off (hit and run).

Because the car behind had a dash cam, he caught the whole thing and could show the driver in front caused the accident and there was no reason to brake (the road ahead was completely clear before the car in front pulled into the lane).

Without that dash cam, the guy behind would have been on the hook.

 

[mikeash]

I think it's important to understand that AP isn't necessarily going to detect vehicles far up ahead that haven't yet locked into the radar system. If it's aware of cars ahead and they slow down, it will reliably slow you down. But depending on it seeing a car already stopped as you approach at 55 mph... that's not something I'd count on. It likely will, but I'd say it's then more about accident avoidance than a TACC speed adjustment and casual stop.

Don't worry, I never count on it and even if I let the car handle it, I'm ready with the brake and don't hesitate to push it if I think we're approaching the point of no return.

I just wrote "we" to refer to me and my car. Hmm....

 

[int32_t]

... I thought AP was breaking a little harder than I would have in that situation, we were down to about 10 mph before we closed to within 3 car lengths with the car in front. Then I heard major screeching behind me and when I looked in the rear view mirror there was a fairly new Mustang with a cloud of smoke from burning rubber coming up. He just barely missed me.

I disengaged AP immediately and pulled forward closer to the stopped cars in front to give a bit more room. It may have made the difference. He finally stopped very close to my car. He probably wasn't paying enough attention, but I did think AP was braking a bit hard for the situation.

I did think it kind of odd when I've seen a lot of people complain that AP doesn't react fast enough or stop hard enough. Maybe an undocumented tweak from the last firmware update? Or just an edge situation.

From the way you describe it, it sounds like Autopilot tried to stop hard, harder than you would have. This left you three car lengths which you wouldn't have had otherwise to avoid the Mustang. Methinks he noticed you farther back than he would have otherwise simply because of Autopilot's hard braking, leaving you enough room to escape trouble and give him room to brake.

 

[CanadaEV]

Today I pulled out of a parking lot, saw the light 100 yards ahead was still green (it's a bit of a wait when it's red), not on AP. I accelerated up to possibly 50 kph (30 mph). The light turned amber, so I released the accelerator, and was coasting, slowing with regen.
Suddenly, there was a van that had pulled out of a parking lot on my right side, making a left turn in front of me. I just missed her. Didn't even see her until she was broadside to me. She had made a very poor calculation, probably based on me exiting a lot, and not being capable of Tesla-like acceleration.

These kinds of things happen. At times like that when you 'own' the road ahead, people can do stupid things. The light turning amber probably saved the situation.

Question: The AP sees the rear of a car ahead, but does it properly see and react to the side of a car perpendicular to you?

 

[RogerHScott]

Question: The AP sees the rear of a car ahead, but does it properly see and react to the side of a car perpendicular to you?

In general you shouldn't count on this, since relative to your path such an object is stationary and we know AP isn't great at
spotting stationary things in your path.

 

[S'toon]

I almost got hit while riding my bicycle today. I was riding through an intersection, light was green, and some idiot decided that the way was clear to turn left. Stopped a couple of centimeters from me.

 

[ItsNotAboutTheMoney]

did you miss the part where it was mentioned that it was a rapid emergency stop? I am surprised the AP reacted so well. there is no gentle/gradual way of making an emergency stop.

No, I didn't. The OP wrote that there was more space in front and said he actively took that space and thinks that it helped.

 

[EV-lutioin]

The blind spot detection doesn't work well enough to be useful. It would be nice if the back-up camera could be used with AP to detect these situations.

I have also wondered about this... my MX does not give me much notice of cars coming from behind or on the side of the car, it would be nice if the backup camera could be utilized for this. And it would be helpful if there was some sort of warning light if there is a car in the blind spot?

 

[BriansBucketList]

I did a trip to Salem, OR and back today and there were actually two incidents while on AP, though if they had resulted in an accident, I don't think either would have been my fault.

AP 2 needs a rear camera to visually see all the cars to the rear and spot this kind of thing. The ultrasonic sensors don't have the range to spot someone two lanes over from moving into the lane you're trying to move into.

.

Agree that slower breaking would be nice when possible, but can you define what the computer code, i.e. If then else should be to determine when the car should brake down to a few feet ? I look at rear traffic often because of this.

 

[rickrickrick]

This is my biggest complaint about my P90D. I find the blind spot detection almost useless. I would have paid extra to have a warning system similar to that in my previous Mercedes. It was flawless. To me, it seems like old technology that is now available on most cars. Can't figure out why Tesla did not include it. Love the car with the exception of a couple of minor items like this.

x2, I agree. Our 2015 Subaru Legacy has a great blind spot detection system I'd love to have in the S. I compensate by driving with the rear camera display at the top of my screen. It's an additional part of my scan before I initiate a lane change, both with and without autopilot.