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Discussion Starter · #1 ·
Hi all,

I have a few questions about City Safety in our vehicles. I have a 2013 S60 without technology package. I know that my city safety is supposed to work up to 31mph and should detect cars and pedestrians (is that right?). I have also read that City Safety is capable of avoiding a collision as long as the speed difference between you and the vehicle in front of you is 9mph or less. If it's more than 9mph, it will attempt to mitigate the crash.


SO, if I'm driving at 9mph and there is a car in front of me, given that all the other criteria are met (no active input from driver, etc...) vehicle will stop and avoid collision. But how about following scenario: I'm approaching a car at 30mph; car in front of me is going 21mph and suddenly slams on breaks and comes to a full stop, before I manage to change the lanes to pass it. Will City Safety work? I guess I would like to find out more about the 9mph number and what is referring to. Is the 9mph cut off for the moment when city safety applies brakes?

Was anyone stopped by city safety, going around 20-30mph because the car in front of you came to a full stop and you didn't react in time? Or would city safety not work?
 

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Approaching a car going 21 mph at 30 mph means your difference in speed is 30 and that you're doing 51... I guess... sorry...

I'm not sure about the numbers; I don't know what the top speed for city safety is or such things but physically you're carrying a lot more kinetic energy at 30 mph then you are at 9 mph. So approaching a stationary car at 9 mph is not the same as catching up a 21 mph car at 30 mph. The bottom line is that if the system thinks you're at an impeding crash it'll sound the alarms (sounds and the blinking in the windscreen). If you still don't react it'll slam on the brakes. As for your second scenario I'm not sure what you mean. If the car in front of you comes to a full stop city safety will do the warning and then brake unless it receives other input from you.
 

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Discussion Starter · #3 ·
If the car in front of me is going 21mph and I'm going 30, in the same direction, the difference between our speeds is only 9mph. also, what are you referring to (alarm, blinking heads up display) is a part of technology package and doesn't come standard with city safety... but thanks for the post anyways!
 

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You might check out these articles on the IIHS website for some good information:
"They're Working" 2012 article describes insurance claim reductions attributed to City Safety and similar systems.
http://www.iihs.org/iihs/sr/statusreport/article/47/5/1
"First Crash Avoidance Ratings Under New Test Program" 2013 article describing test results for several midsize vehicles including Volvo S60. Note that even though Volvo's system didn't win the top slot, it had already been available as standard equipment for 2 model years by this time.
http://www.iihs.org/iihs/sr/statusreport/article/48/7/1
Also of interest is this video from Euro NCAP which performs additional test scenarios - including one which seems pretty close to the one you raised - on a 2013 v40. Not sure if this vehicle has the exact same system as on your S60 though.
https://www.youtube.com/watch?v=xJZfYnZfGuM
Lots more info from these 2 sources if you dig around.
Also many idiots performing their own "tests" as well.
 
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