Re: "seemingly as a result of the camera-based vision system being confused"
On the other other hamd, our Berlingo has similar, yet it overlays that with speed sign recognition from the single camera behind the rear view mirror and 'general knowledge'. This leads to ridiculous situations where you are driving happily on the ring road at 40mph and the system recognises a 20mph limit on a side street.
Or driving through roadworks with temporary speed restrictions where the initial sign is recognised, but if it doesn't spot another one within a few hundred yards, it puts the limit back to the 'normal' for that road.
Or the almost total imability to recognise illuminated signs on motorway overhead gantries, which combined with the above could lead to the thing happily recommending 70mph in a 50mph speed-controlled zone.
Or the 'common sense' which tells it that 'country lanes' are usually 'national speed limit' and insists we can do 60mph ouside our front door in a residential area.
And the thing has the ability (thankfully off by default) to tie this in with the speed limiter, so you could be cruising along nicely on the aforementioned ring road at 40mph and suddenly find the car refusing to respond to the accellerator and slowing down to 20mph.
And the same camera runs the lane departure/nudge-you-back system which gets confused just as easily, particularly where roads narrow and occasionally (but reproducably) has a nasty habit of attempting to steer you into the path of oncoming traffic.
Me, I bought a Dacia with none of this frivolity.
M.