Quick Stops and Adaptive Cruise Control

[AlphaDecay]

Has anyone had a situation where the ACC had to stop the car quickly? There was a discussion about a WRX driver (that is now being charged for their driving) and the WRX had "brake checked" a Lexus driver that was close behind them (the WRX driver had done other things to create that situation from my understanding). Anyway, my friend's comment was that he was surprised at how well the automatic braking of the Lexus worked (he assumed it was that feature due to the distance and speed of response). Has anyone been in the bad spot where the ACC had to stop or brake check? I've never had that issue but it does make me wonder how well it would work. Here's the related youtube of the WRX/Lexus: https://www.youtube.com/watch?v=2Ea2Au13EVY

Edited March 11, 2015 by AlphaDecay

[acdii]

The car will slow down, how much depends on the situation, but it will not stop! It disengages at 25 MPH. What it does do, and is annoying is if a car moves to a turn lane and slows, the ACC grabs onto that car and will slow you down even though it is no longer in your lane. Only if the car in front has moved completely out of the line of sight of the radar and then slow will the ACC ignore it. In this situation, something like what you described could be interpreted as a brake check by someone behind you. Subaru now has the autobrake which WILL stop the car on it's own, but only if another car directly in front of it has stopped.

[jeffo65]

The car will slow down, how much depends on the situation, but it will not stop! It disengages at 25 MPH. What it does do, and is annoying is if a car moves to a turn lane and slows, the ACC grabs onto that car and will slow you down even though it is no longer in your lane. Only if the car in front has moved completely out of the line of sight of the radar and then slow will the ACC ignore it. In this situation, something like what you described could be interpreted as a brake check by someone behind you. Subaru now has the autobrake which WILL stop the car on it's own, but only if another car directly in front of it has stopped.

 

I just replaced my Xterra with a 2015 Subaru XV Crosstrek with the Eyesight system. I got spoiled with the ACC on the FFH and wanted it on my vehicle.

 

I was told by the dealer that Subaru "Eyesight" will assist in the stopping when the vehicle is traveling at a slow speed. I believe it is 30 mph. If you are going faster than that you will get the warnings and adjusted speeds as the FFH does during ACC.

 

Maybe I need to test it out. :)

 

.

[AlphaDecay]

What it does do, and is annoying is if a car moves to a turn lane and slows, the ACC grabs onto that car and will slow you down even though it is no longer in your lane.

 

That part drives me nuts on freeway exits - I've even adjusted to just going to the left lane so I don't get nabbed by people exiting and slowing. I know that ACC won't stop, but I was just wondering how hard it would brake (say from 70 down to 40 or something). The collision warning sensor thing is another added precaution, which is nice. I'm quite happy with all of the driving aids and am actually looking forward to my now driving age daughter using the car (especially with the MyKey stuff).

 

 

I just replaced my Xterra with a 2015 Subaru XV Crosstrek with the Eyesight system. I got spoiled with the ACC on the FFH and wanted it on my vehicle.

 

I can't stand driving my wife's van and when we replace it, the new car will have a similar feature. Out here in Montana there is just too much road distance to not have ACC-like features. Now I just need a replacement that is a hybrid, AWD, increased ride height (like a crossover) and ability to light-duty tow (golf cart on a trailer kind of thing).

[jeffo65]

Even if the cars did auto stop, I am not sure I would fully trust them to do it by itself. I am not ready for a self-drive vehicle.

 

 

 

I can't stand driving my wife's van and when we replace it, the new car will have a similar feature. Out here in Montana there is just too much road distance to not have ACC-like features. Now I just need a replacement that is a hybrid, AWD, increased ride height (like a crossover) and ability to light-duty tow (golf cart on a trailer kind of thing).

These reasons are why I looked at the Subaru Crosstrek. I wanted something that would get good gas mileage, be able to carry my bikes, be able to carry the kayaks and tow a small trailer when needed and have increased ride height.

 

This vehicle served all those things. I passed on the Hybrid because the difference in mpgs was not significant enough.

[md13ffhguy]

The car will slow down, how much depends on the situation, but it will not stop! It disengages at 25 MPH.

Actually, it disengages right around 12 MPH. However, it can't be set until you reach 20 MPH.

[acdii]

Actually, it disengages right around 12 MPH. However, it can't be set until you reach 20 MPH.

MKT is different then, thought the Fusion would be similar. The T engages at 25 MPH, but I never attempted to see where the ACC would quit, not about to either.

[md13ffhguy]

MKT is different then, thought the Fusion would be similar. The T engages at 25 MPH, but I never attempted to see where the ACC would quit, not about to either.

Unfortunately, my commute frequently involves speeds fluctuating between 10 and 25... in a 55 zone. This morning, I probably drove for a good 3 miles under 25, but over 12, with the ACC set at 1 bar, which made the whole experience slightly less frustrating.

[murphy]

At about 20 mph, as the traffic is slowing down, there is a "ding" and the ACC shuts off.

[md13ffhguy]

At about 20 mph, as the traffic is slowing down, there is a "ding" and the ACC shuts off.

The manual, and my actual experience, indicate that this occurs at 12 MPH.

[Waldo]

MKT is different then, thought the Fusion would be similar. The T engages at 25 MPH, but I never attempted to see where the ACC would quit, not about to either.

 

Why not, I do this 3-4 times a day. Very uneventful.

 

The Fusion will disengage at 12mph but the MKT will disengage at 18mph.

[acdii]

Not going to worry about the MKT anymore, I traded it off this evening for a Focus for my wife. My Freestyle should suffice for now for what I used the MKT for, just without all the toys and "style". The Fusion has almost everything the MKT had, except the adaptive HID headlights and suspension, oh and heated steering wheel, and cooled seats, which really weren't, the heated seats in the Fusion are so much better than they were in the T.

[dlubin]

I have been pleased with the performance of the ACC except for one thing. It appears to be overly sensitive to bicycle riders, even if they are far off on the shoulder. When I come up on a bicycle, I often have to hit the gas pedal to keep the car from slowing down. Perhaps the guy who designed the system was an avid cyclist, and wanted to make a statement!

[Riggo]

I've seen that the latest update to Tesla's car allows the car to accelerate, steer, and come to a stop without any input from the driver.

I am wondering why something like this can't be done to those of us who have ACC and park assist in our cars. It seems if the Fusion can slow down and speed up already, a software update to bring it to a complete stop if need be isn't a big deal. And since park assist can steer the car and lane departure brings the car back in the lane already, it could be updated to steer completely and keep the car in the lane.

Come on Ford, hook us up! ?

[lolder]

These functions take a lot of software, computer power and memory and the present cars may not have that. This coming earthquake is about more than self driving cars and some companies may be swamped by the tsunami. Many of them are in a panic trying to catch up. Self driving cars are already here in the Tesla S and to a lesser extent some Volvos, Subarus and some European makes. These are not yet autonomous driverless cars. Google is way ahead in the autonomous software and Tesla is accumulating a million miles of driving data per day in it's fleet of 40,000+ Model S's equipped with the "Autopilot". A recent Tesla software update 7.1 enables the S to be summoned ( on private property ) from it's parking location to you without a driver. It will open a garage door, exit, close the door and drive to you. Those who say these technologies will be here by 2020 or 2025 are going to be left in the dust.

[murphy]

My 2013 Fusion does not have the capability to apply the brakes automatically other than the regen braking which can't stop the car. It pre-charges the brake system and activates an audio and visible warning when it detects a possible collision so that when the driver hits the brake pedal maximum braking is immediately available. It has triggered many times when there is no danger such as the car in front turning out of the lane. The lane following capability is not even close to being good enough to automatically steer the car. I've tried and it wanders back and forth from lane edge to lane edge like a drunken driver. Fortunately it defaults to off in a 2013. I almost never turn it on.

[talmy]

My son has a Tesla (without the self driving features) but had a loaner with those features while his was undergoing routine maintenance. I got to ride in it. It isn't perfect -- it will follow the car ahead into turn lanes rather than keep going straight. It does wander a bit and isn't smooth with speed control (although it is capable of coming to a complete stop if the car ahead stops). I found it drives much like a new driver would. Maybe as the system matures it will get better!.

[hybridbear]

My 2013 Fusion does not have the capability to apply the brakes automatically other than the regen braking which can't stop the car.

I didn't realize that Adaptive Cruise Control can only use regen to slow the car. I thought it also used the friction brakes as needed.

[Riggo]

I didn't realize that Adaptive Cruise Control can only use regen to slow the car. I thought it also used the friction brakes as needed.

I thought that as well. I've had it slow down incredibly fast and didn't think the regen brakes could do that.

[murphy]

I didn't realize that Adaptive Cruise Control can only use regen to slow the car. I thought it also used the friction brakes as needed.

Given the number of times it has gone into heavy braking due to a car that is turning in front of me I'm glad it can't. I know the car will be out of the way long before I get there and have to hit the accelerator to override the braking. The cruise control will take the car down to some low speed that I forget (maybe 12 mph) emit a ding and go off line leaving me to take over.

[murphy]

I thought that as well. I've had it slow down incredibly fast and didn't think the regen brakes could do that.

That is one of the reasons that they try to keep the hybrid battery at 50%. That leaves plenty of room for regenerative braking to charge the battery. The only thing they can do with the friction brakes is get the pump running so the system is at max pressure when the brake pedal is hit. They call it precharging the brakes.

[md13ffhguy]

I didn't realize that Adaptive Cruise Control can only use regen to slow the car. I thought it also used the friction brakes as needed.

It's always been my theory that ACC is nothing more than electronics. Nothing feels mechanical about it. Probably why it can't do a full stop. BTW, I think the collision warning system flashes and beeps when the computer calculates that regenerative braking alone might not be enough, and they've clearly calibrated this warning on the conservative side.

[Waldo]

You guys are completely off. The ACC system absolutely can and does use the friction brakes, just as it does in every other non-hybrid Ford/Lincoln model. The stability control system also applies the friction brakes when needed using the same hardware. However the system can not apply 100% braking power, it only can apply something like 20% of maximum braking, that's why the warning will come on when using ACC sometimes. What might have you confused is that the brakes (friction or regen) are only applied while ACC is active, not when ACC is off and the collision warning comes on. From what I've heard, the main reason the Ford system doesn't do a full stop is because it can't do it smoothly and quietly. Once vehicle speed gets low there isn't enough background noise to drown out the actuator motor sound so Ford figured people would complain and think something was broken. They must have resolved it though, since the 2017 Fusion system will have full-stop.

 

As for the Tesla system, well Tesla doesn't have any unique hardware, their lawyers just don't have as much experience as all the other OEMs yet.

[James Kelker]

The 2017 Fusions can have ACC with stop and go (Ford's term) so can go to a full stop and restart. I think if stopped longer than 3 seconds you have to tap the gas to resume. It will brake hard if needed.

[hermans]

I had a situation the other week with my MKZh on the turnpike. I was traveling along at 70 MPH with the ACC set at the 2nd level. A car came up behind me very fast, passed me and cut back in lane really fast. He immediately braked hard and my ACC immediately kicked in and my car was really breaking hard and the collision warning came on. Turned out there was a cop car on the side o the road. Glad I had the option as I'm not sure I could have reacted that fast and I used to race open wheeled cars and I was a Police Officer with a lot of defensive driving experience.