Strange routing...me or my TomTom

BigPerk · Posted: Wed Aug 26, 2009 11:01 am Post subject:

Doesn't explain WHY, but is there a 'no u-turns thank you' option on the satnav? Might solve this particular problem, though not necessarily any general 'funny-routing' in the algorithm.
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David
(Navigon 70 Live, Nuvi 360)

GerryC · Posted: Wed Aug 26, 2009 11:42 am Post subject:

As I have the WCE map, I can't check but could someone who is affected try the following...

Set up a route from just before the roundabout to just after it. If I'm reading the posts right, this should offer the "detour" route with the U-turn. Now make sure that the status bar has 'time remaining' set and do a demo. Note down what the remaining time is at the beginning of the journey.

Now do the same route with the "shortest route". Again note the remaining time at the beginning but look carefully at the demo at 100% or lower. At any time, does the "time remaining" jump suddenly?

I'm wondering if this is a similar map error to the one that was on a roundabout on the M40(?). Then, the "fastest" route was to go down the motorway and turn around at the next junction rather than turn right on the roundabout at the junction you were on.
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Gerry
TomTom730T
Cameralert for Android
Brodit ProClip mount

Anita · Posted: Wed Aug 26, 2009 12:50 pm Post subject:

Right, I hope I've got this right!

Fastest: 1:45 mins, 0.3 miles
Time remaining counts down until it joins the roundabout, when it jumps from 1:05 to 0:30.

Shortest: 2.25mins, 275 yards
Time remaining counts down until it leaves the roundabout, when it jumps from 2:20 to zero!

Hope that what you want, Gerry.
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Anita
TomTom VIA 135 - App 12.075
UK map 1130.12368
Samsung Galaxy S21

GerryC · Posted: Wed Aug 26, 2009 1:57 pm Post subject:

Thanks Anita. It wasn't quite what I was expecting but those jumps are the cause of the routing error.

I was expecting it to jump between the exit from and subsequent entry onto the roundabout but the "bigger" jump on the shortest route is why it routed the way it did on the "fastest" route.

Not a lot can be done as far as I know except point out the error to TomTom and hope they fix the timings on the next release. The fact that other maps covering the same area appear correct should make this easier but we are talking about TT here. Rolling Eyes

_________________
Gerry
TomTom730T
Cameralert for Android
Brodit ProClip mount

Calomax · Posted: Wed Aug 26, 2009 4:25 pm Post subject:

TomDavison · Posted: Mon Aug 31, 2009 5:56 pm Post subject:

If it's a fastest route problem, try using limited speed, and set your max speed to 70mph. I always use limited speed anyway, with a max speed of 65mph, and this gives me better timing on long motorway journeys.

darrenintheeast · Regular Visitor Joined: Sep 18, 2008 Posts: 78

i've got a new sat nav now.

TomTom XL IQ routes with europe maps....

happy now

docdoc · Posted: Wed Sep 02, 2009 7:54 pm Post subject:

Do you use mapshare? I noticed that I got funny routing after downloading some mapshare updates and I guessed that someone had put some crap correction in that diverted my route away from a certain road, so I changed my mapshare settings to my corrections only.

mpwilson99 · Posted: Wed Sep 02, 2009 8:50 pm Post subject:

maca2 · Frequent Visitor Joined: Jul 10, 2005 Posts: 303

Mapshare was the cause of my strange routing on my 730T, it would take me off the A3 northbound at Guilford then go into guilford then back onto the A3 making the route much longer.
I posted here removed mapshare & it works perfectly but even with just TT mapshare updates loaded the problem returns so it's their mapping/updates that are wrong. I have removed all mapshare updates & no longer use it.

docdoc · Posted: Thu Sep 03, 2009 8:10 pm Post subject:

I tried this route on my Go 740 - v8.37 software and the 815 UK&ROI map. I get the same problem where it turns left at the first roundabout then does a u-turn if choosing the fastest route. On my PDA with v7.9xx software + 835 UK&ROI map it also does this. The 835 Western & Central Europe map is ok.

So must be a quirk with the UK&ROI map data.

There must be a few errors on roundabouts as there's a particular route I takethrough Newcastle-under-Lyme which I know is the fastest route but the TT always calculates a different route. When you get to the roundabout in question, the time to destination suddenly drops by about 8 minutes when you get to the other side! So obviously the TT calculates this as 8 minutes longer than it actually takes!

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