How reliable is City Safety?

ahngau · Nov 19, 2016

Just came across a couple of photos depicting an accident involving an XC90 in Hong Kong. There is no detail about it from the facebook post but it got me thinking. Shouldn't the City Satefy feature prevent this from happening?

It was a clear day without rain or fog or anything which would have impaired the radar or camera. It's a busy street so the driver couldn't have been travelling very fast. I have been racking my brain to see how this can happen except that the car in front reversed into it!

Please share your own experience on how reliable is City Safety. Did it stop your car in time?

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goVolvo · Nov 19, 2016

If driver was pressing the brake but not enough to stop the car, city safety will not engage. This is my understanding.

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carz · Nov 19, 2016

Too many variables to know. If the Volvo driver changed lanes quickly and then the bus braked, there is no way city safety is going to save you. It is a tech assistant, not a miracle maker.

Calhon · Nov 19, 2016

ahngau said:
Just came across a couple of photos depicting an accident involving an XC90 in Hong Kong. There is no detail about it from the facebook post but it got me thinking. Shouldn't the City Safety feature prevent this from happening?

First, the question cannot be answered without details of the incident to compare against City Safety's specific operating paramaters. Second, City Safety will not prevent all collisions.

goVolvo said:
If driver was pressing the brake but not enough to stop the car, city safety will not engage. This is my understanding.

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That is not correct. On the contrary, City Safety will apply up to full braking if the driver isn't pressing the brake hard enough.

Gary-16-Xc90 · Nov 19, 2016

I can confirm what Calhoun said that City Safety will brake harder if the driver is not doing enough to mitigate. I had that experience the a MY16 XC60 as I was about to merge onto I-35 from I-494. The traffic came to an abrupt halt. I thought I was braking hard enough but City Safety activated and braked enough to avoid low speed impact. We were probably going 10 Mph and before it took over.

goVolvo · Nov 19, 2016

Good, another case is when driver is steering, not sure how city safety works.

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BoneDoc · Nov 19, 2016

In that traffic people often go too fast and too close. That's how driving is in the culture. So if the bus suddenly brake, no amount of force can prevent it. Such is physics.

goVolvo · Nov 19, 2016

BoneDoc said:
In that traffic people often go too fast and too close. That's how driving is in the culture. So if the bus suddenly brake, no amount of force can prevent it. Such is physics.

City Safety is not capable enough. In a future autonomous car, it should be able to check the distance and override driver's hard press on gas pedal, don't do unsafe acceleration.

BoneDoc · Nov 19, 2016

Have you driven on those traffic condition? If it’s that restrictive I bet drivers would just turn them off. Safe distance means that you’ll always get cut off

Gorban · Nov 19, 2016

A friend of mine managed to rear end a truck on the highway with his XC60 in slow traffic. The city safety had braked the car to a stand still and when the traffic started to roll again my friend pushed the accelerator, something happened and he ended up in the rear of the truck.

reeg2 · Nov 20, 2016

goVolvo said:
City Safety is not capable enough..

Says who? And why?

goVolvo · Nov 20, 2016

reeg2 said:
Says who? And why?

"In a future autonomous car, it should be able to check the distance and override driver's hard press on gas pedal, don't do unsafe acceleration. "

City Safety doesn't do this currently.

carz · Nov 21, 2016

goVolvo said:
"In a future autonomous car, it should be able to check the distance and override driver's hard press on gas pedal, don't do unsafe acceleration. "

City Safety doesn't do this currently.

Nobody said the XC90 is an autonomous car. Not even with the PA2 it is considered autonomous. They are just driving aids and should be treated as such.

goVolvo · Nov 21, 2016

carz said:
Nobody said the XC90 is an autonomous car. Not even with the PA2 it is considered autonomous. They are just driving aids and should be treated as such.

That's why I am saying it is not capable enough, and still need improvement in future to make driving (at slow speed) safer. I didn't say City Safety at its current stage should be able to do so.

Leafable · Nov 21, 2016

goVolvo said:
If driver was pressing the brake but not enough to stop the car, city safety will not engage. This is my understanding.

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Nonsense. We experience of pressing the brake but the city safe activated full brake because its think we going to crash on to the back of a golf who brake too suddenly. It's all down to the user setting. You never know some idiot switch the City safe off or in "late" setting. We set it to the "early" which quite sensitive.

webusermy · Nov 21, 2016

Leafable said:
Nonsense. We experience of pressing the brake but the city safe activated full brake because its think we going to crash on to the back of a golf who brake too suddenly. It's all down to the user setting. You never know some idiot switch the City safe off or in "late" setting. We set it to the "early" which quite sensitive.

Idiot reporting in.

I have my set in "Late" setting, because while in normal setting for me, at least with the crazy drivers here in Malaysia, the car brakes too hard too often, and I worry more about being hit behind by a tailgater than me hitting someone in front.

Purpleorchid · Nov 21, 2016

Does anybody know what "Earlier", "Normal" and "Later" really mean? The manual (on the phone) doesn't say anything relating to measurements, it just talks about fewer or more warnings. I'm just curious, that's all.

Is it, for example, Normal means x ft (or seconds) before it kicks in warning of impending doom...Earlier means approximately x+y ft...Later means x-z ft.
Or maybe something else like, for example, Earlier gives double the amount of warnings that Normal would give and Later would be half the amount of warnings.
???

I know there is a lot of calculation that the car is doing all the time, so that might be impossible to state in a manual, for fear of lawsuits. But it was just a curiosity question.

GrecianVolvo · Nov 21, 2016

Purpleorchid said:
Does anybody know what "Earlier", "Normal" and "Later" really mean? The manual (on the phone) doesn't say anything relating to measurements, it just talks about fewer or more warnings. I'm just curious, that's all.

Is it, for example, Normal means x ft (or seconds) before it kicks in warning of impending doom...Earlier means approximately x+y ft...Later means x-z ft.
Or maybe something else like, for example, Earlier gives double the amount of warnings that Normal would give and Later would be half the amount of warnings.
???

I know there is a lot of calculation that the car is doing all the time, so that might be impossible to state in a manual, for fear of lawsuits. But it was just a curiosity question.

It is not about the amount of warnings but the relative sensitivity of the system vs distance x speed of your vehicle vs whatever is ahead of you (whether it is still, crawling or moving at a given speed).

gweempose · Nov 21, 2016

GrecianVolvo said:
It is not about the amount of warnings but the relative sensitivity of the system vs distance x speed of your vehicle vs whatever is ahead of you (whether it is still, crawling or moving at a given speed).

So if someone feels that their XC90 is being too aggressive with the braking, setting it to "late" would help to mitigate this?

tillsbury · Nov 21, 2016

Correct. It will depend upon the area in which you drive. For example, here in Christchurch there is still a significant amount of post-quake roadworks around, and sometimes there are tiny wiggly lanes marked with cones. Occasionally you can end up in a situation where you are barrelling towards another vehicle but the cones redirect both of you into narrow lanes around whatever obstacle there is. I've had City Safety sometimes flash up a warning when this relative positioning happens, but setting it later means that I don't get the paranoid auto-braking and thus no risk of someone rear-ending me.

How reliable is City Safety?

ahngau

goVolvo

carz

Calhon

Gary-16-Xc90

goVolvo

BoneDoc

goVolvo

BoneDoc

Gorban

reeg2

goVolvo

carz

goVolvo

Leafable

webusermy

Purpleorchid

GrecianVolvo

gweempose

tillsbury

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