RSA(Road Sign Assist) Issue

[Cyker]

My Mk4 definitely only reads the signs; It couldn't achieve this level of wrongness if it had any kind of GPS or other external database/signal support!

Case in pint: Today it thought a (20) zone was a (120) zone!!  

 

[Yugguy1970]

I saw this exact issue when going round a roundabout yesterday.

Road was 40, first exit road was 20, as I passed this exit the car picked up the 20 sign and then told me the 40 exit and road was a 20.

[Cyker]

All I can say is I hope to smeg this isn't the system they will be linking the mandatory speed limiters with...

 

[Kental]

The Corolla with built in nav throws more anomalies in compared to the Yaris with just the camera, however the Yaris thinking signs are in km rather than miles is something I’ve not noticed with the Corolla yet…

[Wooster]

I have an old (and seldom used) tumble dryer at the far end of my garage.  When I drive in, the round porthole is seen as a 70mph speed sign....

[Roy124]

1 minute ago, Wooster said:

I have an old (and seldom used) tumble dryer at the far end of my garage.  When I drive in, the round porthole is seen as a 70mph speed sign....

Don't believe it, your driver assist won't stop in time 😁

[Tech429]

On 7/5/2022 at 6:00 PM, Cyker said:

My Mk4 definitely only reads the signs; It couldn't achieve this level of wrongness if it had any kind of GPS or other external database/signal support!

Case in pint: Today it thought a (20) zone was a (120) zone!!  

 

I am certain mine does not read signs and works only on GPS files in the memory via the Nav system.  I might be wrong but i feel the "Sign Reading" is just a made up thing.

Most systems work via GPS - due to the fact most signs these days can be obscured by trees, foliage and other obstructions to function correctly.  But like earlier said it probably uses both - the "reading" primary and the GPS "secondary".

[Roy124]

Tech, no, in a short distance mine manages to react rightly or wrongly to temporary signs and also ignore fixed ones instead chosing a previous limit.  Clearly it mixes and mismatches both GPS and Camera at random. 

[Wooster]

39 minutes ago, Tech429 said:

mine does not read signs

Oh, mine reads the signs alright.  (Including my tumble dryer in the garage. 70mph!)  But it also 'sees' the speed restriction signes on the back of lorries.  "This vehicle is limited to 50mph" complete with the round, red perimeter symbol.  My car tells me the speed limit is 50mph even though I'm on a 'National Speed Limit' applies motorway. It also sees the speed restriction on on slip roads - 40mph or 50mph - even though I'm continuing on the 70mph motorway.  The system also relies on the driver taking a sharp turn off the road to reset the system - so if it's a gentle slide onto a slip road (and the spacing of the street lamps tells me it's a 30mph zone) my car will still tell me the fast dual carriageways speed limit applies.  I've switched mine off as it's more trouble than it's worth.  I can't rely on it.

[AndrueC]

3 hours ago, Tech429 said:

I am certain mine does not read signs and works only on GPS files in the memory via the Nav system.  I might be wrong but i feel the "Sign Reading" is just a made up thing.

Most systems work via GPS - due to the fact most signs these days can be obscured by trees, foliage and other obstructions to function correctly.  But like earlier said it probably uses both - the "reading" primary and the GPS "secondary".

Using both is the only sensible way to implement such a system. GPS can give you the official limit for the road but there can always be temporary restrictions in effect.

I would hope that Toyota have programmed it with regard to the law and signage. That might explain some of the odd behaviour. Speed limit signs have a 'duration' so once read any others should probably be ignored for a certain distance. For sure GPS should be.

[Cyker]

6 hours ago, Tech429 said:

I am certain mine does not read signs and works only on GPS files in the memory via the Nav system.  I might be wrong but i feel the "Sign Reading" is just a made up thing.

Most systems work via GPS - due to the fact most signs these days can be obscured by trees, foliage and other obstructions to function correctly.  But like earlier said it probably uses both - the "reading" primary and the GPS "secondary".

The Yaris definitely is a 'Sign Reader' - It doesn't have a GPS or satnav system so that's the only way it could possibly work. The fact that I occasionally get 120 and even 160 speed limits flashing up supports this as no way would even a hybrid GPS system allow such ridiculous inaccuracy!  

 

 

[Kental]

14 hours ago, Cyker said:

The Yaris definitely is a 'Sign Reader' - It doesn't have a GPS or satnav system so that's the only way it could possibly work. The fact that I occasionally get 120 and even 160 speed limits flashing up supports this as no way would even a hybrid GPS system allow such ridiculous inaccuracy!  

 

 

It does have a GPS, but no mapping or speed limit data. It uses its own GPS for eCall and MyT.

[eyemdee]

I have come to the conclusion that the speed limit display uses GPS data which can be overridden by the camera reading the signs. There is a stretch of road with a new 30 limit which I regularly use and it always displays 40mph travelling East but 30mph when travelling West. It was the same in my previous Corolla. There is no 40mph sign for it to read when travelling East so it must be the old GPS data, but when travelling West it reads the 30 signs as you enter the village. I have also noticed it reads advance warning signs when you are approaching a 30 limit and changes the limit to 30 as you pass the first sign 300 yards before the limit actually starts.

[Roy124]

Eyemdee, I have reported a similar anomaly, it's at Great Casterton.  In that 30/30 gap the limit is signed at 40 going the other way. 

Once in the 30 zone it sees a 20 sign for a road that branches off.  It next sees a 50 sign before immediately changing to 60 even though it is still a 50.

[AndrueC]

It also reads countdown signs so where they are present will report the speed limit as lower than it actually is for a couple of hundred yards.

And I've mentioned before that it will read the undersized speed limit signs used in Scotland to specify a limit applicable only to HGVs. If you drive the A75 the car will continuously tell you that the speed limit is 40 mph.

[Swanthecat]

My system only recognises 2 types of signs. The first is a motorway sign it picks up as I drive past the motorway junction on a 30mph A road. The second is on a particular stretch of road where it always picks up a National speed limit sign. Every other sign indication I am pretty sure comes from the GPS since at one point locally the speed signs are obscured by trees/bushes. If you look on page 363 and 364 of the online owners manual it gives some indications of the types of signs it reacts to. These look very different to the UK type signs. Could this be the cause of most problems?

[Tech429]

Well if it does read signs then I'm not a believer!

Once entered into a 50mph area it does state 50mph... then changes accordingly (70 in a 70, etc.).

But sometimes it shows me the national speed limit sign (white with black diagonal line) but no such sign in sight - although a 70 sign there.  Some days it does show 70 but other days it show the other sign.  Very temperamental if you ask me.

So I really do think it is only picking up GPS and what the database has recorded as being the speed limit.

Even Tom Tom has the facility to amend such errors and once amended on the next update it has been corrected.  That tends to be more correct from what I have experienced so far.

[eyemdee]

1 hour ago, Tech429 said:

Well if it does read signs then I'm not a believer!

Once entered into a 50mph area it does state 50mph... then changes accordingly (70 in a 70, etc.).

But sometimes it shows me the national speed limit sign (white with black diagonal line) but no such sign in sight - although a 70 sign there.  Some days it does show 70 but other days it show the other sign.  Very temperamental if you ask me.

So I really do think it is only picking up GPS and what the database has recorded as being the speed limit.

Even Tom Tom has the facility to amend such errors and once amended on the next update it has been corrected.  That tends to be more correct from what I have experienced so far.

Mine definitely does read signs with the camera. I passed through some road works the other day with a temporary 40 mph speed limit. The sign is partially obscured by bushes in one direction and does not register on the display but in the opposite direction the sign is unobstructed and registered on the dashboard as I passed it. I have also encountered the (derestricted) national speed limit symbol on the dash on occasions.

[Cyker]

Mine definitely does - It thinks a lot of the A406 is 20mph because of the signs on the side roads  

[50p]

7 minutes ago, Cyker said:

Mine definitely does - It thinks a lot of the A406 is 20mph because of the signs on the side roads  

Normally the A406 doesn't even reach 20mph! 🤣

[Cyker]

That's a good point  

[Chuffmonkey]

3 hours ago, Tech429 said:

Well if it does read signs then I'm not a believer!

Once entered into a 50mph area it does state 50mph... then changes accordingly (70 in a 70, etc.).

But sometimes it shows me the national speed limit sign (white with black diagonal line) but no such sign in sight - although a 70 sign there.  Some days it does show 70 but other days it show the other sign.  Very temperamental if you ask me.

So I really do think it is only picking up GPS and what the database has recorded as being the speed limit.

Even Tom Tom has the facility to amend such errors and once amended on the next update it has been corrected.  That tends to be more correct from what I have experienced so far.

Mine reads the signs. On a 30mph road near work it displays 30mph which is the correct speed. Half way down this 30mph road somebody has decided to turn a 20 mph side road sign, to face the main road. The car then displays the 20mph limit until I arrive at work which is still defiantly the same 30mph road. 

I have also seen it display the no overtaking sign (Black/Red car) whilst going through road works on the A51 in Stafford recently. 

[AndrueC]

6 hours ago, Tech429 said:

Well if it does read signs then I'm not a believer!

Once entered into a 50mph area it does state 50mph... then changes accordingly (70 in a 70, etc.).

But sometimes it shows me the national speed limit sign (white with black diagonal line) but no such sign in sight

Probably it has been programmed with the rules set out by law. Speed limit restrictions only apply for a certain distance and require repeaters. If the car hasn't seen a specific limit sign for a certain distance it will be informing you that the limit has reverted to the default for that type of road.

A 50mph single carriageway road is not 50mph for a driver because it's been designated as such in a database. For a driver it is only a 50mph road if there are repeater signs at appropriate intervals.

6 hours ago, Tech429 said:

- although a 70 sign there.  Some days it does show 70 but other days it show the other sign.  Very temperamental if you ask me.

Not sure what you're saying there but the cameras are indeed far from perfect so it's entirely possible that it sees a sign one day but not the next depending on how your car was positioned with respect to the sign as you pass it.

6 hours ago, Tech429 said:

So I really do think it is only picking up GPS and what the database has recorded as being the speed limit.

And you're wrong 😉

Many of us have incontrovertible proof that the camera overrides GPS. If you actually think about it there can be no other way to program it. If the car only relied on GPS and a database it would be unable to react to temporary restrictions in roadworks.

[Cyker]

If it isn't sure it usually shows a speed limit circle sign with the numbers blank, e.g. ( _ _ )

I've only ever had it show the national speed limit sign when there has been a sign that looks like the national speed limit sign (But also faded signs that have a similar look, e.g. one that is has a crossout indicating the end of a 20 zone and another sign I can't remember off the top of my head)

The system does seem to be programmed with a generic bank of signs as it randomly flashes up signs that we don't use here but another user (Was it you stopeter??) said is a French sign, and it also randomly thinks the signs are in kph instead of mph which has the knock-on effect of the overspeed warning going red (I seriously hope they do something about that before they turn on the hard speed limiters!!)

[Roy124]

Andrue, there is a stretch of road, A43, not far north of you that has random temporary 50 mph signs.  Most times my car does not see the start and will equally randomly decide it is a 50 zone later on.  The interval is hugely in excess of 200 m.

Not far from here in Lincolnshire are two areas with temporary 40 signs.  Some signs have been flattened.  A derestriction sign in in a non compliant design, and there have been no signs of any activity meriting the restrictions.  I challenged Highways who in turn will be contacting the contractors.

On another stretch the road has had surface dressing with the usual chipping 20 mph advisories, however one contractor has interspersed the advisories with mandatories.  Needless to say, most motorists ignore the limit especially when the chippings have gone.

We should challenge non compliant or inappropriate road works signs as it will only lead to ignoring them when they should really be obeyed.