ASL Automatic Speed Limiter

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Jsuter
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Post by Jsuter »

Does anybody knows if the XC40 has this feature ?

The Automatic Speed Limiter (ASL) reads road signs and adapts the vehicle's maximum speed to the posted speed limits.
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wakey
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Post by wakey »

Yes it does 👍
Black (inside and out) XC40 First Edition D4, 20” Wheels and a dog grille :D Collection Saturday 7th April (ordered 6th January).
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Jsuter
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Post by Jsuter »

Tx super cool !
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Whiterdesign
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Post by Whiterdesign »

It will be the same as my XC 60 and I use it a lot find it very good. One of the problems it seems to have is when you are driving on a road say with a 50 limit and you come to a roundabout with a side road off with say a 30 limit, it picks up the 30 sign as you are going round the roundabout , so when you want to accelerate out of the roundabout you can’t . Got used to it now, just temp switch it off on the steering wheel and back on when it sees the 50 sign again. Doesn’t happen a lot but seems to happen about 50% of the time when I drive down a road near me which I use a lot. Also happens on the road where I live, which is a culdesac. If I come in from one direction it picks up the sign, if from the other still thinks it’s a 30 limit.
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Boomer
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Post by Boomer »

Well tried and I won't be using it (ASL) in normal circumstances (well not the normal commuting run). Problem is that the sign recognition does seem to be very sensitive and picks up the signs on adjoining roads - so for example I'm on a 30 but then it spots a 20 on a side road and puts on the brakes. Grrr! Switch off and then on again. And it then picks up the next 20 on the next side road a 100 yards down the road and brake back to 20 limit. Very frustrating. Yes you can up the threshold but that resets every time it sees a new sign.

So ASL (for me) is not going to be regularly switched on - perhaps only whilst driving in an area that is new to me?. I'll keep with the SL only function for the moment - that acts as a helpful reminder.
XC40 FE [MY18] | T5 AWD Auto | Crystal White | 20" | Lava | Apr 18
PC40
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Post by PC40 »

I’ve noticed this as well but was not using the ASL at the time! Worst one was passing a builders yard with a 5mph yard limit. Car thought that was main road limit instead of 30mph. Traffic speed was only 2mph at the time!
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morrishey
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Post by morrishey »

From my downloaded manual...

“Automatic speed limitation takes place using speed information from the RSI function - not from the speed limit road signs that the car passes.”

When I was testing the car, I’m sure I was told that the limit info comes from a database built into the mapping system, which ties in with the above. So, errors are maybe not a result of the car misreading signs, but of errors in the database or just GPS accuracy meaning the car thinks it has moved into the new restriction.
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Boomer
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Post by Boomer »

I thought RSI captured radar data as well. My mistake.

Either way my car is picking up side road data and making the wrong decisions for ASL.

Going to have to research this more, and wonder if it might also be why I've got those weird speed camera findings (see other thread).
XC40 FE [MY18] | T5 AWD Auto | Crystal White | 20" | Lava | Apr 18
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Boomer
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Post by Boomer »

Much confused - the manual sets out the following (which to me seems to suggest that RSI needs to SEE something and is not relying on a database!? [Perhaps at best it looks for signs and then compares to a database - but the starting point might be that it needs to see it first] so spotting side road signs and similar makes ASL pretty useless. It is my growing conclusion that all the "aids" have a time and place, but not always for day to day use.

Limitations of Road Sign
Information
The Road Sign Information (RSI95) function may
have limitations in certain situations.
Examples of what can reduce the RSI are as follows:
• Faded signs
• Signs positioned on bends
• Rotated or damaged signs
• Signs positioned high above the roadway
• Fully/partially obscured or poorly positioned
signs
• signs completely or partly covered with frost,
snow and/or dirt
• digital road maps96 are out-of-date, inaccurate
or have no speed information97.
XC40 FE [MY18] | T5 AWD Auto | Crystal White | 20" | Lava | Apr 18
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Boomer
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Post by Boomer »

Boomer wrote: Fri Apr 20, 2018 3:23 pm It is my growing conclusion that all the "aids" have a time and place, but not always for day to day use.
And why fully autonomous cars are such a large leap.
XC40 FE [MY18] | T5 AWD Auto | Crystal White | 20" | Lava | Apr 18
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