The only thing I can think of is if you were traveling at under 4km/h at the time? Citysafe doesn't function below 4km/h as it assumes you are parking.
If that isn't the case & you aren't getting a failure message then perhaps a dealer visit may be in order to have them check that all is well.

 

P223 of my Manual has a section called "City Safety - limitations".

Are you familiar with these?

City SafetyTM - limitations
The sensor in City SafetyTM is designed to detect cars and other large vehicles in front of the car irrespective of whether it is day or night.
However, the function does have some limitations.

The sensor's limitations mean that City Safety has poorer functionality - or none at all - in e.g. heavy snowfall or rain, dense fog, dust storms or white-out situations. Misting, dirt, ice or snow on the windscreen may also disrupt the function.
Low-hanging objects, e.g. a flag/pennant for pro- jecting load, or accessories such as auxiliary lamps and bull bars that are higher than the bonnet limit the function.
The laser light from the sensor in City SafetyTM measures how the light is reflected. The sensor cannot detect objects with low reflection capacity. The rear sections of the vehicle generally reflect the light sufficiently thanks to the number plate and rear light reflectors.
On slippery road surfaces the braking distance is extended, which may reduce the capacity of City SafetyTM to avoid a collision. In such situations the ABS16 and ESC17 systems will provide best possible braking force with maintained stability.
When your own car is reversing, City SafetyTM is temporarily deactivated.

City SafetyTM is not activated at low speeds - below 4 km/h (3 mph), which is why the system does not intervene in situations where a vehicle in front is being approached very slowly, e.g. when parking.

Driver commands are always prioritised, which is why City SafetyTM does not intervene in situations where the driver is steering or accelerating in a clear manner, even if a collision is unavoidable.

When City SafetyTM has prevented a collision with a stationary object the car remains stationary for a maximum of 1.5 seconds. If the car is braked for a vehicle in front that is moving, then speed is reduced to the same speed as that maintained by the vehicle in front.
On a car with manual gearbox the engine stops when City SafetyTM has stopped the car, unless the driver manages to depress the clutch pedal beforehand.

Appologies for poor quality copy/paste (note: my emphasis).

 

It might be you weren't close enough. At very low speeds it will stop almost instantly and is designed to be a last resort. If you have a large cardboard box (empty!) you could try driving at it and seeing if the car stopped?

 

Many thanks for all your replies and suggestions. I think it could have been that I was below the minimum speed simply.

I was not aware of the limitations - thanks for the clarifications. Much appreciated!

 

maybe you could try it out using a big carton box? My colleague had tried that with his mazda and it failed, whereas his newer VW stopped for the box!

 

My car has stopped when I approached an automatic barrier at work. The barrier is reflective and very close to the front of the bonnet when I pull up to the card reader. I now use an entrance where the barrier is slightly further away from the car!
A message came up on the speedo display to say that the feature had activated. I was surprised because I was hardly moving.

It won't work on a card box box because it won't reflect the laser.
As the spec says it needs reflective surface like the rear of a car or number plate.

 

Ah yes, my focus also does that!
It seems like Volvo/Ford have exchanged more than only the chassis on these siblings!

 

I tested mine on large TV box, and it stopped successfully both times that I did the test. Can't judge the reflection properties of that box though. The speeds that I tested it with were around 20-30 kph, can't remember now precisely.

 

We did this about 5 times on day two of getting the car. 55" tv box in the middle of the road. Great fun.
Works well.



Just remember the city safe is different from pedestrian detection... hahaha