What model vehicle are you driving?

 

2019 XC90 T6 Inscription

 

Hmmm, I'm driving a 2019 XC90 T8 and I have the same question about my City Safety.

I've heard you can put a traffic cone with reflective tape on it in a parking lot, and drive toward it at like 30 MPH, and it should activate.

I have such a traffic cone, and it's in my car. I may go to the Sear's parking lot, since it's empty, and try driving towards the cone.

 

I just recently experienced the effectiveness of the system in a real-world event. As I was driving along a city street, doing about 30mph, a car driving alongside me from the left suddenly cuts in front of me to get to a gas station, triggering the system. It was impossible to ignore, with sudden beeping and the brakes engaging hard. No doubt that it spared us from getting in an accident.


Sent from my iPad using Tapatalk

 

Just don't try this:

 

That is totally moronic to do. I have seen the system work with the reflective cone.

 

I’ve seen other tests like this as well. Apparently the system is set up to watch for motion, and doesn’t work well with static objects. Like a person, vehicle or other object crossing from one side to the other.


Sent from my iPad using Tapatalk

 

I always thought of doing a test like this myself - But I know between my 17' V90CC and 17' XC90 - the city safety has absolutely worked. Only once when it stopped me did the Dash actually say "City Safe Activated" - the other times I get beeps and automatic braking.

 

My understanding is that it will not attempt to stop if the object is small enough. Anytime sudden braking is applied, there is always the hazard of rear-end collision. If it is a small animal crossing, many times it is safer as a whole (but not the animal crossing) if no braking is applied.

If it were the size of a moose, my guess is City Safety will be activated.

In the first few weeks of my SPA xc90 ownership, there is a surface road that widens, but at the point where the road widens, is the beginning of street parking. As a result, driving there would appear to head towards the first parked vehicle before any clues from the steering wheel would indicate (to an automated system) that collision will be avoided. I recall lights and beeping in response, but I don't recall any braking. There was another instance on the surface road where I slowed down to a red light gradually, but it appears that the system thinks my deceleration rate isn't sufficient to avoid the vehicle stopped in front. The system applied some braking at that time.

There were 2 or more instances since then, all in the first few months of ownership where braking was applied as if the system was extra nervous. But since then, I haven't experienced the false braking. It is possible that there is at least 1 parameter that the system adapts over time, and that the driver(s) are also adapting to the system over time.

Testing this type of system is challenging, because we don't know what exact factors are being monitored, and what the thresholds of those factors are. Iirc, there was recent news about the new Suzuki Jimny driven by auto journalists in North America exhibiting behavior not previously noticed when used in markets it was already available at. The way these black boxes "see" the world isn't necessarily the same as how humans see it.

 

My car was hit by a boy riding bicycle crossing in front of me from my right cutting corner on left side of his road. Car braked. The boy fell down but not hurt. The handle of the bike left a dent on my car fender. Lucky time.

Sent from my Z978 using Tapatalk

 

I had nothing to do this afternoon, so I wanted to test some of my new Volvo's safety features and see how well they work without crashing into anything. So I started with City Safety. According to the manual:

So my unscientific test was that my wife and son took a large blanket and held it up across my driveway. I was thinking the car would "see" the blanket and think it was another car.

• I started the car and let the computers boot and settle.
• I put the car in drive and took the foot off the brake.

So the car was idling, I assume going 5mph or less. The car "beeped" as it approached the blanket but proceeded to drive right through the blanket. The brakes were not apprised.

Shouldn't the car have tried to apply the breaks and try to stop?

The car may not have seen the blanket as an issue 1) not moving, the camera needs motion 2)not thick enough and soft, the Radar may not have seen it.

 

City Safety is deactivated below 5 km/h (3 mph)

 

I know it works. (It might even be predictive like the Tesla system?)

I was confused about a juncture and doing the indicator dance (sorry giving Volvo drivers a bad rep). Traveling around 15mph. Had to choose left or right at the fork. I was chose right, but was also looking at the sign on the left. Then I felt the brake pedal drop with ABS feeling and the City Safety bong. The car in front of the car in front of me had come to a complete stop pretty quickly. When the Volvo got my attention, the car in front of the car in front of me's back end was dropping down from a hard stop. The funny thing is the car directly in front of me did not have its brake lights on, and when the brake lights turned on for the car in front of me moments laters it appeared to be hard stop too.

This is why I am thinking maybe the Volvo radar can see the car in front of the car some how (not a typo, I know this has some grammatical errors in my writing). It appeared to detect the stopped car in front of the car directly in front of me, prior to the car in front of me began braking. Anyways thats my story.

Maybe our Volvo's have this capability? https://electrek.co/2016/09/11/elon...09/11/elon-musk-autopilot-update-can-now-sees-ahead-of-the-car-in-front-of-you/

 

Couple of weeks ago driving home from work in traffic at 30mph. Food truck is in front of me, fairly heavy traffic. Suddenly the food truck slams brakes on. City Safety icon goes off. I reacted instantly to the food truck hitting the brakes. I braked very hard. Definitely an 'oh, sh*t' moment. I don't know how much was me and how much was City Safety but I stopped in time.

Turned out car 3 ahead of me slammed on brakes to make a sudden u-turn, car behind it rear ended it, food truck then rear ended that car.

I thought I was going to be rear ended but guy behind me swerved into the shoulder, rather than plow into me.

Volvo brakes worked well. I stopped several feet short of the food truck. The vehicles in front of me were messed up, major damage.

 

This is why I think ACC should be always enabled to keep a reasonable interval even on city streets. Pressing brake should not disengage it.

Sent from my Z978 using Tapatalk

 

I've had our 2011 (first gen) City Safety slam on the brakes when I come into the garage too fast. Doesn't like the edge of the door opening coming up fast and close on the passenger side.

 

same here. I tend to fly into my garage and know my vehicle placement pretty precisely. Sometimes my XC60 isn't so happy with me doing that and slams on the binders. Kind of annoying but a small price to pay for the added safety in real world.

 

So a couple technical notes on how the system works:

- It uses "sensor fusion" (aka, some weighted combination) between the forward looking (black and white) camera behind the windscreen and the variable beam width radar.

- The radar is not well-equipped to detect stationary objects, and many of the "city safety" features are heavily dependent on the camera.

- The camera isn't looking for blankets or cones. It's a trained convulutional neural network, and is trained on real pictures of bicyclists, pedestrians, and large animals. The pedestrian detection is therefore dependent on the object actually looking like a human/animal. It doesn't look for "obstructions" (as it might then slam on the breaks in the snow/rain/car wash/etc) it actually looks for things that match the outline/movement/contour of the stuff it was trained to detect.

- The camera also aids in ACC by detecting cars when the radar isn't quite sure what it's seeing.

- Both the radar, and the camera system especially (including Pilot Assist) are probabilistic systems. It's all a FPGA accelerated neural network. It doesn't work in absolutes. So it has to have "high confidence" the thing you're about to hit is a real thing, before it intervenes. Additionally, it will stop intervening if it thinks you, the human, are in control. It will only fully apply the brakes if you do nothing. It's also not designed to like, "prevent you from hitting" the object, necessarily anyway, it's designed to slow down enough to prevent you from killing a pedestrian/cyclist/etc.

Let me find the safety test videos where they run these systems through their paces. Pay particular attention to the "test objects" they use, and you'll see what I mean about the camera.

EDIT:

YouTube video of the EuroNCAP testing setup:

 

I had nothing to do this afternoon, so I wanted to test some of my new Volvo's safety features and see how well they work without crashing into anything. So I started with City Safety. According to the manual:

So my unscientific test was that my wife and son took a large blanket and held it up across my driveway. I was thinking the car would "see" the blanket and think it was another car.

• I started the car and let the computers boot and settle.
• I put the car in drive and took the foot off the brake.

So the car was idling, I assume going 5mph or less. The car "beeped" as it approached the blanket but proceeded to drive right through the blanket. The brakes were not apprised.

Shouldn't the car have tried to apply the breaks and try to stop?

With that kind of test at 5mph its more likely it was a "parking event" and the only sensors to pick up the blanket were park sensors and not necessarily camera & radar. It's what allows you to pull into a spot and not repeatedly engage brakes as you try to pull into your spot, garage, or other similar situation. Imagine how annoying that would be!

As for CitySafety, I've had it engage a number of times since we've had our T8. At least two were actual situations where the car reacted before I did and I was glad. In those situations the belts pre-tightened anticipating a collision. The others were semi false alarms usually while driving down a street with cars parked on both sides (residential street) that I have to drive around and occasionally the system would anticipate I might hit one of the parked cars. It would alarm and brake. I probably shouldn't have been driving as fast (30-40km/h) while weaving between the parked cars . I've not experienced it with a live obstacle jumping in front of me like an animal or pedestrian.

 

First two times it activated in my V60 was in a controlled situation: moving toward a chain link fence with a couple traffic cones in front of it; worked like a charm both times.

Next time was a surprise as I was exiting a parking garage and the gate wasn't working as quickly as it could have...

Last time was in stupid stop and go traffic with bastard gangsters in the right merge lane deciding yielding is a sign of weakness and trying to cut those of us proceeding forward; activated for a car in front of me that suddenly slowed when he got gangstered...not sure I needed it, but saw the message that it activated...pretty slick to have as a backup IMHO...YMMV​

 

When City Safety first was introduced, I happened to be at the Volvo dealer, and witnessed a test being done in the parking lot.

They were using an inflatable clown standing on a dolly. The rope tugged on the dolly to create motion like the person is jaywalking about 20' in front of approaching car. The auto-braking system was activated, and the car stopped a couple of feet short of the target.

 

I tried driving towards a traffic cone at 30 MPH yesterday in a mall parking lot, and the City Safety did not activate. So either this is not a good test of this function, or the City Safety is not working on my vehicle. My money would be on the "this is not a good test" option.

 

City Stop



I can tell you that it definitely works. Not a good feature to play with. I have an S90. On the freeway here in California, someone abruptly pulled in front of me and the car stopped. I was held in so tightly, I had difficulty breathing, however, I did not hit the car.

 

The Volvo dealer you purchased the car from should have a demonstration kit - I know mine did. It's similar to the foam rear-end of a car seen in youtube videos and Motorweek shows.
I tested a loaner against it and found it worked every single time, even with the demonstrator car stationary at speeds less than 30mph.

At "parking speeds" though, the system will not activate.

 

The Volvo dealer you purchased the car from should have a demonstration kit - I know mine did. It's similar to the foam rear-end of a car seen in youtube videos and Motorweek shows.
I tested a loaner against it and found it worked every single time, even with the demonstrator car stationary at speeds less than 30mph.

At "parking speeds" though, the system will not activate.

Those no longer exist.

 

My City Safety has engaged just once, when I came up my driveway faster than usual and approached the still-rising garage door. I was on track to enter my garage with clearance to spare, but the City Safety apparently didn't like the combination of the car's speed and the distance to the moving garage door.

 

I experienced both positive and faulty system's engagement.

Once I approached the traffic light and Iw as 4th of 5 th car and I had about 2 length distance from the tac in front of me, we are were barely moving with same speed and when my kiddo asked for water bottle I turned toward him and almost immediately system get triggered with alarm, braking, and seat belt tightening - I immeatelly turned around and noticed a dog crossing the road in front of the car that couple cars ahead of me. so 2 cars stopped and system stopped my car too. we both were pretty shocked as it was prety new car to us ..
Sometimes (more than once) system kicked in (alarm only and very brief braking, no belt action) when I drive on the narrow one-way street with cars parking on both sides and road curves slightly; so at some point car thinks (?) I'm going into a parked vehicle. Not sure if should complain about it to a dealer. Is anything could be done about it?

 

Sometimes (more than once) system kicked in (alarm only and very brief braking, no belt action) when I drive on the narrow one-way street with cars parking on both sides and road curves slightly; so at some point car thinks (?) I'm going into a parked vehicle. Not sure if should complain about it to a dealer. Is anything could be done about it?

I have a similar experience (post #9 above), but only in the beginning of my ownership. I still pass by the same slightly curving & narrow path with parked vehicles slightly in the way if the path were straight. But no more alerts so far (~ 1 year passing that road about once a week). Maybe parts of the system adapts over time.

 

You can adjust the sensitivity of City Safety, just try to reduce it.

 

Indeed; I always reduce mine to "later" on every vehicle I drive and it eliminates extra alarms.

 

From personal experience, this system works. It alarmed and braked at night while we were on a highway and a dark-colored car with NO lights on moved in front of us. Also did the same, but without the braking, for a construction barrel that was in front of us but placed at the apex of a curve so it wasn’t a real hazard (dunno if the system made that determination). We like the system and it’s worked well for us. I wonder more about the animals and people function. It’s never triggered for the numerous deer that are on the side of the road waiting to ruin our XC! It also hasn’t triggered for people that walk in front of us but admittedly, I’m normally already on the brake. I no longer want to be a stuntman (although “The Fall Guy” theme song sometimes comes into my mental soundtrack) so I’m not willing to verify it works...

 

Works well! It avoided 2 possible rear-end events due to other drivers fault, a cut in then slam on brakes during heavy traffic.