Car speed restrictions on Satnav

[kochanski]

I have a 2021 Corolla with its new Satnav, My previous car displayed the official speed restrictions on the Satnav screen, not just what the screen camera picked up as displayed on the speedometer. Does this feature still exist? I can't find it and it was useful.

[AndrueC]

The limit shown on the dashboard includes information from sat nav mapping on models that have sat nav. Signs seen by the camera will override the map information.

Anyway you shouldn't rely on the car to tell you. The camera can fail to see signs and see signs from roads you're not driving on. The sat nav maps can be wrong (I've been trying for three years now to correct the map for a road outside my estate).

[Trewithy]

As I drive into Tesco's car park there is a 10 MPH sign which registers in the car.  However on leaving there is no sign to say the limit  on the road ahead is 30 MPH, so I drive down the main road with a red warning sign on the dash until I get to the 40 MPH zone one mile down the road.

[bigblock]

9 minutes ago, Trewithy said:

As I drive into Tesco's car park there is a 10 MPH sign which registers in the car.  However on leaving there is no sign to say the limit  on the road ahead is 30 MPH, so I drive down the main road with a red warning sign on the dash until I get to the 40 MPH zone one mile down the road.

Yes I get this alot too. I use a stretch of dual carriageway that's set at 50mph but there is a 30mph slip road sign that runs along side the dual carriageway and alerts me I am going too fast. It's certainly not a system to rely on. Makes me wonder what is going to happen when the new vehicles with auto speed limiters get on the roads. I can see alot more accidents happening if these limiters get spooked. Which they will. 

[Catlover]

Difference is… Trewithy’s is 100% accurate on the report he states. Hi camera picked up the 10mpg sign, that was the last sign the camera saw. Can’t get better then that, no sign..nothing to read, not the cameras fault.

but I agree with you, Michael, these devices will have to be more accurate. However, if a camera is put in a poor place it is hardly the car makers fault.

[bigblock]

13 minutes ago, Catlover said:

Difference is… Trewithy’s is 100% accurate on the report he states. Hi camera picked up the 10mpg sign, that was the last sign the camera saw. Can’t get better then that, no sign..nothing to read, not the cameras fault.

but I agree with you, Michael, these devices will have to be more accurate. However, if a camera is put in a poor place it is hardly the car makers fault.

Yes Joe. This is where things are going to get very interesting in the future. An accident is caused by a misplaced speed sign that the driver has no control over. The vehicle was just doing it's job my lord.

[forkingabout]

My current vehicle displays the speed limits via the connected, built in ( & fully up to date ) Tom Tom satnav - it still displaying the wrong speed limit for a local road 18 months + after the highways agency reduced the speed limit.

Automatic speed restrictions for vehicles is years away from being useful / safe for roll out as both newer camera systems & older sat nav based systems are not ready yet.

[bigblock]

31 minutes ago, forkingabout said:

My current vehicle displays the speed limits via the connected, built in ( & fully up to date ) Tom Tom satnav - it still displaying the wrong speed limit for a local road 18 months + after the highways agency reduced the speed limit.

Automatic speed restrictions for vehicles is years away from being useful / safe for roll out as both newer camera systems & older sat nav based systems are not ready yet.

Speed limiters will be on all new vehicles built after July this year if the European rule goes ahead in the UK. The Uk government wants to retain this rule even though we are supposed to have left the EU now? Time for even more new infrastucture on the roads of Britain? That's on top of these fabulous smart motorways we are having. Wonderful.

[AndrueC]

3 hours ago, Catlover said:

Difference is… Trewithy’s is 100% accurate on the report he states. Hi camera picked up the 10mpg sign, that was the last sign the camera saw. Can’t get better then that, no sign..nothing to read, not the cameras fault.

but I agree with you, Michael, these devices will have to be more accurate. However, if a camera is put in a poor place it is hardly the car makers fault.

It should use the sat nav though. Mine does. Although it's actually incorrect, if you turn off the A43 Northbound at Brackley (Dual Carriageway) onto the A422 towards Banbury (single carriageway) the car will show a limit of 50 mph. There is no speed limit sign (apparently not needed because both roads are NSL) so the only way the car can know about the change in limit is via a sat nav system. I wonder how models that don't have sat nav fair?

 

 

[Stopeter44]

11 hours ago, forkingabout said:

Automatic speed restrictions for vehicles is years away from being useful / safe for roll out as both newer camera systems & older sat nav based systems are not ready yet.

The camera based system in the Yaris, for example, is only as good as what it’s given or can see.

Leaving mine, I go past a clearly visible 30 kph sign, this is shown by the RSA on the dash. The end of 30 zone sign doesn’t exist. The car continues to show 30 kph. If I take, after that, one road out of the village I’m on the the autoroute, according to the RSA. In reality it’s a twisty B road, but there’s no indication, as such, when leaving the village.

Unfortunately, RSA is not conveniently turned off.

[Catlover]

9 hours ago, AndrueC said:

It should use the sat nav though. Mine does. Although it's actually incorrect, if you turn off the A43 Northbound at Brackley (Dual Carriageway) onto the A422 towards Banbury (single carriageway) the car will show a limit of 50 mph. There is no speed limit sign (apparently not needed because both roads are NSL) so the only way the car can know about the change in limit is via a sat nav system. I wonder how models that don't have sat nav fair?

You stated your sat nav is incorrect. What about updating the software on sat nav. Does it update as you using the satnav or wait until it’s updated by the car manufacturer, which some people do not bother with. 

[AndrueC]

3 hours ago, Catlover said:

You stated your sat nav is incorrect. What about updating the software on sat nav. Does it update as you using the satnav or wait until it’s updated by the car manufacturer, which some people do not bother with. 

Eh? As I've mentioned before the problem is the map itself and I have tried several times over the last three years to edit it. Each time it seems someone reverts the edit. I checked it last weekend and so far no one has reverted my last edit so I'm hopeful that the next sat nav update might finally include the fix.

[kochanski]

Thanks for all these replies. The reason I posted originally is that I too have found the dash speed showing 30mph when I have turned onto a dual carriageway where the max is 70. Some development needed I think.

[Kental]

I find our Yaris speed limit detection Unreliable on variable speed motorways, especially the larger single ones on the side rather than the gantries over the lanes.

[Roy124]

Kental, on a particular A road my system did not see the temporary 50 signs on both sides of the road.  Some distance later it picked up a single 50 reminder sign.  Yes, unreliable at the moment. 

Under the new system going too slow will be a pain and going too fast pain of a different sort. 

[Cyker]

I swear mine has gotten less accurate since I've had the car  

It keeps randomly picking up 20mph limits on 30 and 40mph roads, but also sometimes picks up 50, 60, 70 and 80 signs from god knows where on anything from 20 to NSL roads  

It is another thing that has trained me to mostly ignore it!

 

[AndrueC]

44 minutes ago, Roy124 said:

Kental, on a particular A road my system did not see the temporary 50 signs on both sides of the road.  Some distance later it picked up a single 50 reminder sign.  Yes, unreliable at the moment. 

Under the new system going too slow will be a pain and going too fast pain of a different sort. 

Going too fast already leads to pain either legal or worse. No-one should be relying on their car to keep them informed of the speed limit. Treat it as a useful backup for those times (hopefully rare) when you are temporarily unsure.

[twintopp]

yeah its got a long way to go before it will be 100% accurate 100% of the time what with the trend of reducing speed limits, new roads etc. you would have to have speed limit signs every couple of hundred yards, i think it`s something we will just have to put up with for the time being .

[Kental]

On 2/1/2022 at 10:19 AM, kochanski said:

Thanks for all these replies. The reason I posted originally is that I too have found the dash speed showing 30mph when I have turned onto a dual carriageway where the max is 70. Some development needed I think.

On a dual carriageway our Yaris will generally pick up the NSL sign, it is joining a 70 limit motorway that doesn’t clarify the speed it struggles with.

[Stopeter44]

46 minutes ago, Kental said:

On a dual carriageway our Yaris will generally pick up the NSL sign, it is joining a 70 limit motorway that doesn’t clarify the speed it struggles with.

Aside from its own limits, it's only ever as good as the signage it can see. It sees a motorway on the B road out of my village !

[AndrueC]

10 hours ago, Stopeter44 said:

Aside from its own limits, it's only ever as good as the signage it can see. It sees a motorway on the B road out of my village !

Also as I've noted before recent(ish) legislation means that there doesn't need to be a speed limit sign when going from a dual carriageway to a single carriageway if both are NSL. In this situation the only way a car can know the speed limit is by having access to a map.

[Stopeter44]

I paid more attention to that transition, and in fact what happens is that the road goes from 80 kph at the exit from the village, it's the normal, or county/department* speed limit, then at the entry to the next village, there's a 70kph sign, and then there's a no more speed limit sign. It's after that sign that the RSA says motorway.

* In France the speed limits are set by departments, or counties, some of them are 80 kph and some of them are 90 kph.