Cruise control / Collision avoidance failure

[A3r03ng]

Hello,

I was driving my Mach-E Tuesday Apr. 4, morning when I had an accident. I was approaching a roundabout, which is always congested, so I set the adaptive cruise control to 30km/h and joined the queue. Adaptive cruise control automatically follows the flow of traffic, starting, driving, and stopping when required, in time with the car in front of it. I use this feature every day, and it has always worked fine. However, on Tuesday, after a few minutes of driving, the car suddenly started and crashed into the car in front of me! Both cars were damaged, but fortunately, no one was hurt.

Note that I used the cruise control in the queue way before the roundabout, not in the roundabout. It is a straight road, single lane, and I usually deactivate the cruise control about 50-100m before reaching the roundabout.

I wanted to share this story as a warning to other drivers who use adaptive cruise control. I have asked the car dealer, but they're not sure what caused the car to suddenly accelerate. They actually didn't know that this feature could be used in the traffic...

I'm also curious to know if any other Mach-E owners have experienced anything similar. If you have, please be so kind as to share your story. I can't believe I am the only one to have experienced this.

(Quite a few issues reported here, in relation to cruise control behaviour: https://www.nhtsa.gov/vehicle/2021/FORD/MUSTANG%2520MACH-E/SUV/AWD)

Thanks!

Another interestingly weird fact. My car is not fixed yet, and the front sensor and camera are out of service. However, I still find myself trying to turn on the adaptive cruise control out of habit. It doesn't work, obviously and warns me that the crash sensor is defective... except that, from time to time, it still engages, and shows the car in its blue bubbles on the dashboard, as if everything is under control. However, it is not, and the car keeps trying to drive into other cars! I suspected this would happen of course and after testing once, I'm not using it anymore. In my opinion, this indicates a defect in the safety system, which could be the very reason of the accident in the first place, i.e. failure to shut down the adaptative cruise control system when a sensor has failed.

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[MidwestElectric]

Yes I have. Not an accident though. My feeling is current technology is unable to perceive stationary objects as obstacles accurately. Or cross traffic that is perpendicular to the line of travel where there is essentially no relative motion between the object and your car sensor other than the velocity of the car. I drive 50 miles on country roads every day for work, averaging about 55 to 60 mph. Frequently cars will drive across anywhere from 100 to 300 feet away. Never has the collision alert or emergency brake gone off. They will work appropriately when there is sudden slowing of traffic moving in the same direction. My consensus is to avoid using it in slow traffic and always be wary of cross traffic (pedestrian or vehicular).

 

[Blue highway]

Yes I have. Not an accident though. My feeling is current technology is unable to perceive stationary objects as obstacles accurately. Or cross traffic that is perpendicular to the line of travel where there is essentially no relative motion between the object and your car sensor other than the velocity of the car. I drive 50 miles on country roads every day for work, averaging about 55 to 60 mph. Frequently cars will drive across anywhere from 100 to 300 feet away. Never has the collision alert or emergency brake gone off. They will work appropriately when there is sudden slowing of traffic moving in the same direction. My consensus is to avoid using it in slow traffic and always be wary of cross traffic (pedestrian or vehicular).

if an object is stopped, it will not be detected by the radar, because radar reflective things that are not in motion must be filtered out or the car would stop for road signs and over passes. This is true for all radar based emergency braking systems.

It also uses the camera and there are lots of conditions where these don't do well... dark, fog, into the sun, dirty glass, etc. The So-What is that stopped objects, objects with poor radar cross section, objects that are hard to see by the camera are all problematic for automatic braking.

It's helpful to understand how these things work... to anticipate where they will have problems.

 

[Mach1E]

if an object is stopped, it will not be detected by the radar, because radar reflective things that are not in motion must be filtered out or the car would stop for road signs and over passes. This is true for all radar based emergency braking systems.

It also uses the camera and there are lots of conditions where these don't do well... dark, fog, into the sun, dirty glass, etc. The So-What is that stopped objects, objects with poor radar cross section, objects that are hard to see by the camera are all problematic for automatic braking.

It's helpful to understand how these things work... to anticipate where they will have problems.

Not sure that I buy this explanation.

Car is designed and built to be able to use cruise control, even to a complete stop. It should (and is) able to detect stationary objects.

Something clearly went wrong.

That said, when I used adaptive cruise and the car comes to a complete stop, I have a prompt on the screen and have to hit a button to “resume,” the car won’t accelerate from zero without input from me. Are European models different?

 

[Blue highway]

Not sure that I buy this explanation.

Car is designed and built to be able to use cruise control, even to a complete stop. It should (and is) able to detect stationary objects.

Something clearly went wrong.

That said, when I used adaptive cruise and the car comes to a complete stop, I have a prompt on the screen and have to hit a button to “resume,” the car won’t accelerate from zero without input from me. Are European models different?

https://arstechnica.com/cars/2018/0...adar will detect,overhead signs, and so forth.

https://www.nissan-global.com/EN/INNOVATION/TECHNOLOGY/ARCHIVE/MOD/you may want to do some research on how the systems work. Can not detect stationary objects.

What went wrong was potentially a failure to understand how these systems work and their limitations.

 

[Gungrave223]

I almost rear ended someone on the highway yesterday using blue cruise.

There was a slow down in traffic and instead of slowing down with the car in front me... The car pre collision warning came on instead and I had to manually slam on break.

I usually never trust adaptive cruise control on any car but blue cruise was doing so well that I thought I could just let it break as well ... Never again.

 

[Mach1E]

https://arstechnica.com/cars/2018/06/why-emergency-braking-systems-sometimes-hit-parked-cars-and-lane-dividers/#:~:text=A car's radar will detect,overhead signs, and so forth.

https://www.nissan-global.com/EN/INNOVATION/TECHNOLOGY/ARCHIVE/MOD/you may want to do some research on how the systems work. Can not detect stationary objects.

What went wrong was potentially a failure to understand how these systems work and their limitations.

Probably why Ford uses a combination of radar and cameras for adaptive cruise:

https://www.ford.com/technology/driver-assist-technology/adaptive-cruise-control/

Maybe YOU should do some research on how the systems work (isn’t very nice when someone else says it, is it? )

 

[Rt1AWD]

That is why I set to keep the maximum distance from the car in front and try to pay attention all the time.

 

[Mach-Lee]

I've also observed adaptive cruise control try to creep into the car in front of me twice after stopping, which required manual braking to avoid a slow rear end collision. Hasn't happed recently however. You need to pay attention during the delay period and be prepared for the 1 out of 200 times it will try to creep into the car in front of you.

On non-Blue Zone roads the resume delay is 3 seconds
On BlueCruise HF roads the resume delay is 30 seconds

You need to pay attention during this delay period after stopping in case it decides to automatically start moving again by mistake.

There was a slow down in track and instead of slowing down with the car in front me... The car pre collision warning came on instead and I had to manually slam on break.

There is a maximum braking rate while on Adaptive Cruise Control, if collision warning goes off YOU MUST MANUALLY BRAKE HARD. This is not a flaw or a glitch, it's by design. If you expect the car to do all the emergency braking for you, you will hit someone.

In theory collision avoidance may trigger eventually but that should not be relied upon since it doesn't avoid all accidents, especially at high speeds.

 

[A3r03ng]

Not sure that I buy this explanation.

Car is designed and built to be able to use cruise control, even to a complete stop. It should (and is) able to detect stationary objects.

Something clearly went wrong.

That said, when I used adaptive cruise and the car comes to a complete stop, I have a prompt on the screen and have to hit a button to “resume,” the car won’t accelerate from zero without input from me. Are European models different?

I don't buy the explanations either.
Good point. Same here in Europe (Belgium), except that if the cars stops for less than 30 seconds (or one minute, or less, not sure) it can move forward again without having to push the button. If it stops for a longer time, then it will not restart unless you push the button. I (used to) find this very convenient for a fast moving traffic, with very short stops.

 

[A3r03ng]

https://arstechnica.com/cars/2018/06/why-emergency-braking-systems-sometimes-hit-parked-cars-and-lane-dividers/#:~:text=A car's radar will detect,overhead signs, and so forth. https://www.nissan-global.com/EN/INNOVATION/TECHNOLOGY/ARCHIVE/MOD/you may want to do some research on how the systems work. Can not detect stationary objects. What went wrong was potentially a failure to understand how these systems work and their limitations. What is wrong is that when a system fails to work, a fail-safe system should take over or it should just stop and alert the driver, not put the user in an unsafe situation, especially driving assistance, which can safely be deactivated. Because indeed, there always is a probability of component failure. All of this can be calculated with components MTBF, failure trees, etc. This is the basics of system design

 

[RedStallion]

Yes I have. Not an accident though. My feeling is current technology is unable to perceive stationary objects as obstacles accurately. Or cross traffic that is perpendicular to the line of travel where there is essentially no relative motion between the object and your car sensor other than the velocity of the car. I drive 50 miles on country roads every day for work, averaging about 55 to 60 mph. Frequently cars will drive across anywhere from 100 to 300 feet away. Never has the collision alert or emergency brake gone off. They will work appropriately when there is sudden slowing of traffic moving in the same direction. My consensus is to avoid using it in slow traffic and always be wary of cross traffic (pedestrian or vehicular).

Judging from how the car follows the turns on the road I would say the cameras lookahead is probably about 10ft. Radar detectors should have a better range, over 100ft, but judging from how the car adapts to the speed of the cars ahead and when it issues the collision warning, the actual range seems to be far shorter.

 

[Auto Motive]

Hello,

I was driving my Mach-E Tuesday Apr. 4, morning when I had an accident. I was approaching a roundabout, which is always congested, so I set the adaptive cruise control to 30km/h and joined the queue. Adaptive cruise control automatically follows the flow of traffic, starting, driving, and stopping when required, in time with the car in front of it. I use this feature every day, and it has always worked fine. However, on Tuesday, after a few minutes of driving, the car suddenly started and crashed into the car in front of me! Both cars were damaged, but fortunately, no one was hurt.

Note that I used the cruise control in the queue way before the roundabout, not in the roundabout. It is a straight road, single lane, and I usually deactivate the cruise control about 50-100m before reaching the roundabout.

I wanted to share this story as a warning to other drivers who use adaptive cruise control. I have asked the car dealer, but they're not sure what caused the car to suddenly accelerate. They actually didn't know that this feature could be used in the traffic...

I'm also curious to know if any other Mach-E owners have experienced anything similar. If you have, please be so kind as to share your story. I can't believe I am the only one to have experienced this.

(Quite a few issues reported here, in relation to cruise control behaviour: https://www.nhtsa.gov/vehicle/2021/FORD/MUSTANG%2520MACH-E/SUV/AWD)

Thanks!

Another interestingly weird fact. My car is not fixed yet, and the front sensor and camera are out of service. However, I still find myself trying to turn on the adaptive cruise control out of habit. It doesn't work, obviously and warns me that the crash sensor is defective... except that, from time to time, it still engages, and shows the car in its blue bubbles on the dashboard, as if everything is under control. However, it is not, and the car keeps trying to drive into other cars! I suspected this would happen of course and after testing once, I'm not using it anymore. In my opinion, this indicates a defect in the safety system, which could be the very reason of the accident in the first place, i.e. failure to shut down the adaptative cruise control system when a sensor has failed.

Yes at times going under 50mph. Our GTPE did not slow down as the car ahead put on their brakes. I always us the adaptive cruise for safety concerns now at 75 yr I assumed it is faster then me or is It?

 

[Gungrave223]

I've also observed adaptive cruise control try to creep into the car in front of me twice after stopping, which required manual braking to avoid a slow rear end collision. Hasn't happed recently however. You need to pay attention during the delay period and be prepared for the 1 out of 200 times it will try to creep into the car in front of you.

On non-Blue Zone roads the resume delay is 3 seconds
On BlueCruise HF roads the resume delay is 30 seconds

You need to pay attention during this delay period after stopping in case it decides to automatically start moving again by mistake.



There is a maximum braking rate while on Adaptive Cruise Control, if collision warning goes off YOU MUST MANUALLY BRAKE HARD. This is not a flaw or a glitch, it's by design. If you expect the car to do all the emergency braking for you, you will hit someone.

In theory collision avoidance may trigger eventually but that should not be relied upon since it doesn't avoid all accidents, especially at high speeds.

It kinda defeats the purpose of adaptive cruise control especially handsfree driving if the car doesn't "adapt" to the change in the flow of traffic, no?

 

[RickMachE]

When using any cruise control, keeping your foot over the brake pedal when necessary, or the accelerator (when causing on the open highway in case it recognizes a speed decrease), is how you should be using it.

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