How does it know this? - Page 4

coolcat · 14th July 2016, 10:18

Quote:

Originally Posted by Kennyeth

I understand all that Harry, also it does sound far fetched that thinking the GPS could know about congestion/delays.
Just curious and would like to see the reason why the OP gets the messages.
Ken.

Not far fetched Ken, out of this world

As already said, the GPS system doesn't have any maps let alone traffic info!

It is purely a system to allow products to get a grid location.

Any maps, traffic info etc is a seperate product just using the GPS location system to overlay onto their maps.

That's how it works, full stop, end of story

andymc · 14th July 2016, 12:06

I seem to recall reading something ages (years) ago that it's possible to "deduce" congestion from the fact that a high number of satnav-equipped cars are all concentrated together and either stationary or moving very slowly along the same stretch of road. The only experience I have of using satnav is via the maps app on my phone, so I've no idea if this is true or nonsense!

SCP440 · 14th July 2016, 15:08

The next time it does this I am going to take a picture of the screen.

It could be some time as I have no plans to go anywhere but local for the next months.

HarryM1BYT · 16th July 2016, 11:40

Quote:

Originally Posted by andymc

I seem to recall reading something ages (years) ago that it's possible to "deduce" congestion from the fact that a high number of satnav-equipped cars are all concentrated together and either stationary or moving very slowly along the same stretch of road. The only experience I have of using satnav is via the maps app on my phone, so I've no idea if this is true or nonsense!

Sorry, impossible.

A SatNav is just a receiver, a quite complex receiver, but still receive only. They cannot transmit back to the GPS satellites nor to other GPS receivers.

The now switched off TMC(?) system, with which some 75's were equipped, was able to deduce congestion by the flow speed of vehicles on the road. You would get a congestion report on the dash, before becoming entangled, but that is really all it did.

MikeJohn · 16th July 2016, 11:45

But bear in mind what I believe Google do. They can track the position of Android phones, and when a large number of phones are all heading in the same detection, and all start to slow down it is probably the best source of real time traffic information there is.

So Google maps can certainly be updated by this, but its the phone location doing it - not the sat-nave as such.

Mike

mystabe · 19th July 2016, 07:04

It does/did indeed - and it used to be brilliant because you could have it set on your phone to 'traffic view' on your way to and from work on busy motorway commutes, it just showed colours relating to the speed of traffic rather than the full map and it was accurate enough to enable you to see probable gaps in queues in the inside lane at motorway exits so you could jump the queue........ then they made it 'better' and that feature disappeared

SCP440 · 21st August 2016, 23:06

I am sure this is me not understanding the system but the unit today gave me some options to get around a traffic problem up ahead.

And here is the evidence.

And a few mins later as I dismissed it the first time

SCP440 · 21st August 2016, 23:11

So I ask the question again, how does it know this? I have never used that piece of road before in this car so there is no history, My mobile phone was not on wireless hot spot and the Bluetooth was not on. No coaches around so it was not getting any info from them or there free Wifi.

DaPol · 22nd August 2016, 08:40

If I were guessing, I'd suggest it's similar to Tomtom's IQ routes feature - the map has data of average traffic flows in the area embedded in it and knows that between time A and time B road C tends to be congested, and will suggest avoidance based on this historical knowledge - that it happens to map onto what's happening here and now for you is just a feature of the same thing having happened often at the same time on the same day on the same road in the past.

"It be half past three on the third monday of the month, 'appen be there be cows on the road as Farmer Jones moves fields at that time - best avoid that bit" basically.

rab60bit · 22nd August 2016, 09:19

Quote:

Originally Posted by DaPol

If I were guessing, I'd suggest it's similar to Tomtom's IQ routes feature - the map has data of average traffic flows in the area embedded in it and knows that between time A and time B road C tends to be congested, and will suggest avoidance based on this historical knowledge - that it happens to map onto what's happening here and now for you is just a feature of the same thing having happened often at the same time on the same day on the same road in the past.

"It be half past three on the third monday of the month, 'appen be there be cows on the road as Farmer Jones moves fields at that time - best avoid that bit" basically.

That sounds sensible (and I don't even pretend to understand or use any of this stuff). The live screen shot does state "potential congestion detour"?

14th July 2016, 12:06	#32
andymc Posted a thing or two Wedgewood Connie SE / Black Club SE Join Date: Jan 2014 Location: Ballymoney Posts: 1,459 Thanks: 542 Thanked 583 Times in 365 Posts	I seem to recall reading something ages (years) ago that it's possible to "deduce" congestion from the fact that a high number of satnav-equipped cars are all concentrated together and either stationary or moving very slowly along the same stretch of road. The only experience I have of using satnav is via the maps app on my phone, so I've no idea if this is true or nonsense! __________________ My blood brother is an immigrant A beautiful immigrant My blood brother's Freddie Mercury A Nigerian mother of three

21st August 2016, 23:06	#37
SCP440 I really should get out more....... MG ZT-T 260 Join Date: Feb 2016 Location: Witney Posts: 2,504 Thanks: 6 Thanked 910 Times in 571 Posts	I am sure this is me not understanding the system but the unit today gave me some options to get around a traffic problem up ahead. And here is the evidence. And a few mins later as I dismissed it the first time Last edited by SCP440; 21st August 2016 at 23:07.. Reason: Made a mistake

14th July 2016, 15:08	#33
SCP440 I really should get out more....... MG ZT-T 260 Join Date: Feb 2016 Location: Witney Posts: 2,504 Thanks: 6 Thanked 910 Times in 571 Posts	The next time it does this I am going to take a picture of the screen. It could be some time as I have no plans to go anywhere but local for the next months.

16th July 2016, 11:45	#35
MikeJohn Avid contributor Rover 75 Tourer CDTi Join Date: Nov 2006 Location: Bisley Posts: 230 Thanks: 32 Thanked 42 Times in 40 Posts	But bear in mind what I believe Google do. They can track the position of Android phones, and when a large number of phones are all heading in the same detection, and all start to slow down it is probably the best source of real time traffic information there is. So Google maps can certainly be updated by this, but its the phone location doing it - not the sat-nave as such. Mike

19th July 2016, 07:04	#36
mystabe Posted a thing or two Mazda 6 Join Date: Dec 2013 Location: Wigan Posts: 1,384 Thanks: 266 Thanked 398 Times in 287 Posts	It does/did indeed - and it used to be brilliant because you could have it set on your phone to 'traffic view' on your way to and from work on busy motorway commutes, it just showed colours relating to the speed of traffic rather than the full map and it was accurate enough to enable you to see probable gaps in queues in the inside lane at motorway exits so you could jump the queue........ then they made it 'better' and that feature disappeared

21st August 2016, 23:11	#38
SCP440 I really should get out more....... MG ZT-T 260 Join Date: Feb 2016 Location: Witney Posts: 2,504 Thanks: 6 Thanked 910 Times in 571 Posts	So I ask the question again, how does it know this? I have never used that piece of road before in this car so there is no history, My mobile phone was not on wireless hot spot and the Bluetooth was not on. No coaches around so it was not getting any info from them or there free Wifi.

22nd August 2016, 08:40	#39
DaPol Loves to post 75 CDTi Saloon Join Date: Jun 2010 Location: Bolton Posts: 302 Thanks: 47 Thanked 77 Times in 49 Posts	If I were guessing, I'd suggest it's similar to Tomtom's IQ routes feature - the map has data of average traffic flows in the area embedded in it and knows that between time A and time B road C tends to be congested, and will suggest avoidance based on this historical knowledge - that it happens to map onto what's happening here and now for you is just a feature of the same thing having happened often at the same time on the same day on the same road in the past. "It be half past three on the third monday of the month, 'appen be there be cows on the road as Farmer Jones moves fields at that time - best avoid that bit" basically.