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Discussion Starter · #1 ·
Hello,

The Traffic Sign Recognition should be a great driving aid.

Like many urban areas a 20 mph speed limit has been applied to some of the the roads where we live. There are now several boundaries between a 30mph to 20 mph limit.

Most of the time the lower 20 mph speed limits are painted onto the road surfaces rather than a road sign or the signs by the road side are small

And 9 times out of 10 the car displays a 30mph limit in a 20 mph zone. (It feels as if the the information is being taken from Jaguar's own navigation system that is not updated)

How can the TSR more accurately reflect the true speed limit?

I do not use Jaguars navigation system and use apps such as Waze though clearly we do not use either on these shorter journeys.
 

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Not sure what it works from, a live camera or the nav memory. I have definitely had the car warn me about things like no overtaking in a temporary roadworks situation which wouldn't have been in the nav maps. But other times as you say a local area becomes a 20 not a 30 and the car persists in telling me it's a 30.

Maybe the 4G card picks up some info?
 

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It works from a combination of camera recognition and map data. If the camera can see the speed limit sign it usually captures it, but otherwise it reverts to navigation data which is not always up to date. I regularly drive through a village near my home where the speed limit was changed from 40 to 30 some time ago. There are some 30 repeater signs but I find the car is constantly swapping between 30 from the signs and 40 from the incorrect map data. The system is a guide, but not foolproof.
 

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Discussion Starter · #4 ·
Thanks.

A random hit and miss driving aid is not a great help to man or beast.

There must be a way to keep the map/navigation data updated for when the camera does not recognise a road symbol. Perhaps Jaguar need to borrow from other apps that incorporate live ongoing updates to their maps. Or perhaps they just need to better integrate these apps into their cars. Even better, do both.
 

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You can report map errors on the here website (here is the underlying mapping provider), but its very clumsy to report wrong speed limits - it seems to capture that in short sections of road, I gave up last time I looked at it. The camera indeed is looking for road signs and trying to interpret them, its unsurprisingly prone to confusion. I find it often picks up 20 limit signs for side roads when you are driving along the main road, its also very poor at reading variable speed limits on the motorway overheads. Overall I think its a useful feature and its right more than its wrong, but you can't rely on it.
 

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I have found the camera more reliable than the one on my previous Mercedes which often used to pick up speed limits from joining roads. That said no system can be foolproof and you need to use it only as a guide. I'm pleased to have it and with the digital display I have the car speed, speed limit and cruise control speed adjacent to one another which I find really helpful
 

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mattrapier said:
I find it often picks up 20 limit signs for side roads when you are driving along the main road
I was driving the other day using cruise control on a motorway at 110 km/h - the TSR suddenly showed 70 (km/h) ! And then went back to 110 after a while. As the phenomenum repeated again, I found out that as some exit ramps show 70, this value was captured by the camera.
I just wonder what has happened if I was not using that day the cruise control, but the "TSR and Adaptive Speed Limiter" !? Probably that the new speed limit would be set to 70, i.e., the car would have slowed down to 70 despite my effort (foot on the gas pedal) to keep it at 110, until a new 110 sign appeared on the motorway ...
Anyone experienced such situation ?
 

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Discussion Starter · #8 ·
Yes.

A3 out of London is generally 50MPH once near Morden.

Many side roads have 30 MPH signs.

Even though car was in cruise control at 50MPH and nothing in front it would slow down on meeting these signs for the side road speed.

Far from perfect.
 

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I just wonder what has happened if I was not using that day the cruise control, but the "TSR and Adaptive Speed Limiter" !? Probably that the new speed limit would be set to 70, i.e., the car would have slowed down to 70 despite my effort (foot on the gas pedal) to keep it at 110, until a new 110 sign appeared on the motorway ...
No it wouldn't have. If the speed limit spotted by the vehicle is >30km/h under your current speed the car just displays a warning, it's only if it's <30km/h that the car will apply the brakes on its own.
 

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Thanks for the clarification, shadow. It is obviously much safer ... Nevertheless, a fellow driving at, say, 95 km/h in this scenario would be forced to reduce his speed (down to 70 km/ h) from time to time ... Or avoiding to use the Adaptive Speed Limiter. BTW, is it exact that if the TSR is present, there is no way to use the 'basic' limiter, i.e., the limiter is always coupled with the TSR ?
 

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No you can deactivate it, just select the limiter then press cancel for a few seconds it will switch between basic limiter and limiter+TSR
 

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shadow said:
No you can deactivate it, just select the limiter then press cancel for a few seconds it will switch between basic limiter and limiter+TSR
How do you like it? Is it easy to override if the setting is too slow? I'm very interested in this feature because I think it will be comfortable to use. I have no problem with sticking to the speed limits. Safety first!
 

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I tried it once and it made me loose 20km/h pretty fast (50 > 30) due to a roadwork sign, you have to be hit "cancel" pretty fast if you want to overide it.
You can adjust it so it allows you to go up to 10km/h (5mph) over the limit.

I'm not confortable with that feature as I never used a limiter on previouses cars, however I do use the regulator as soon as I can.
Unfortunately the regulator don't take speed limits into account but the adaptive feature is brilliant.
 

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In my 2018 car the adaptive cruise control is about keeping a sensible distance from the car in front, limited to the speed set by the driver. It has nothing to do with the speed limit detected for the road. Equally, the automatic emergency braking is entirely about whether you are about to collide with an object, in which case it flags a driver intervene warning and only in the most extreme case will it do an emergency brake for you (I have never had this happen). The speed limit detection isn't very reliable, it certainly picks up random signs from side roads, and it only occasionally spots motorway gantries. Its better than nothing, but the driver certainly needs to make their own judgement on the current actual limit. So do newer models have automatic adjustment of the speed limiter? That's not going to work until speed limit signage is a lot easier for a machine to read!
 

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As I said no they don't.

update : I misread you, the cruise control won't adapt to the speed detected by the TSR, the speed limiter will.
 

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mattrapier said:
So do newer models have automatic adjustment of the speed limiter?
As indicated by JLR for their "adaptive cruise control"
https://drive.infomaniak.com/app/share/ ... 64976b1368
and their "TSR and Adaptive Speed Limiter"
https://drive.infomaniak.com/app/share/ ... 4b66779484
the automatic adjustment following TSR applies to the speed limiter (if the ASL feature is activated - thanks, shadow !), but not to the (adaptive) cruise control.
 

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shadow said:
As I said no they don't.
Hmmm... I can see how that is a bit 'strange'. So what you are saying is that it is only this-or-that function? Not possible to start the adaptive cruise and then also select the the intelligent speed limiter, together, by user selection and preference.
 

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Precisely, you can't use both as one replaces the other (same button / same spot for the indicator on the screen behind the steering wheel).

So you choose either Speed limiter OR Adaptive Speed Limiter (Traffic Sign Recognition) OR Adaptive Cruise Control (adapts to the car in front of you)
 
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