TomTom Route Recalculation Problem

[runner_bean]

I have a TomTom OneXL and my wife has a GO520. We find that the OneXL will recalculate a route very promptly and intelligently after the driver has declined to follow the recommended route, whilst the GO520 won't recalculate until the unit has been driven miles off the recommended route, even though the new route chosen by the driver is the optimum alternative to the recommended one. This problem is so bad that my wife has given up on her unit, as it has failed her in town centres!

Is there a setting we need to tweak on the GO520, or is this a known problem we have to live with?

 

[dhn]

I do know that many mapping algorithms refuse to consider passing through town centres as part of the route.

 

[runner_bean]

Today we used the GO520 to get from a rural location to a local village ten miles away, following an A road.. The recommended route ended up taking us to a river with no bridge across! We turned back to whence we had come for two miles and then drove another two miles along the A road in the only possible direction that would get us across the river. All this time the GO520 told us to turn around. I am confident that my OneXL would have gone along with our choice of route and replanned to follow the best alternative. Don't understand and not pleased!!

 

[dhn]

And what is the map version on the 520?

 

[Arno]

Today we used the GO520 to get from a rural location to a local village ten miles away, following an A road.. The recommended route ended up taking us to a river with no bridge across! We turned back to whence we had come for two miles and then drove another two miles along the A road in the only possible direction that would get us across the river.

If you don't mind, post the starting and finishing coordinates (or nearby, if privacy is a concern).

I would like to see what my 930 with the v910 Europe map would make of it.

 

[runner_bean]

Arno, we were trying to navigate from TQ568047 along the A27 to Rodmell. The recommended route took us via the A26 to the old bridge at Southease (TQ428053) which has not been fit to drive over for many years/decades (see this link: http://www.geograph.org.uk/photo/3431939). The turning off the A26 to the bridge was marked dead end so we turned around, went back to the A27 and drove West which is correct for an alternative route to Rodmell, but the GO520 refused to replan a route until we had reached TQ424100 in Lewes. That's my gripe.

The GO520 nap is the one it was purchased with (UK updates are ridiculously expensive as our road system changes so little).

If I get a chance I will try a side by side check of my OneXL with GO520 to see when/how they behave differently.

 

[dhn]

That still doesn't tell me what the map version on the 520 is.

Tap the bottom right of the status bar on the 520. The next screen shows the application version installed on the device. What does that show? (The latest is 9.510).

Now, tap that version number and the following screen shows more info including the map installed and its version. So, your screen should show something like UK followed by a number. What is that? (The latest is 910.XXX).

 

[runner_bean]

The app version is 9.510 (I updated it recently). More details are App 9.510.1234792.1, OS 842337 and Map: 'United_Kingdom_and_Republic_of_Ireland' v715.1703.

 

[dhn]

That map version is at least SIX years old. Not surprising that the routing it would suggest on that map would be inaccurate or out of date.

 

[runner_bean]

Have you looked at the photo link I provided? The bridge over the river hasn't been safely usable since the Second World War, let alone six years ago!!

In any case, my complaint is that the GO520 didn't carry out a recalculation when I turned back from the blocked road until I had gone so far that had I not known the other routes in the area I would have been completely lost. I will carry out a side by side test of the GO520 and my OneXL and let you know what happened. I believe that the OneXL will cope.

 

[canderson]

Have you looked at the photo link I provided? The bridge over the river hasn't been safely usable since the Second World War, let alone six years ago!!

And there's every chance that problems of this nature have since been corrected. That is the problem with old maps. Not only do you not receive benefit of changes that have actually taken place over the period of six years, errors discovered in that period may also not be available to you. If by some chance a Mapshare correction fixes the problem, that's a lucky thing. If not, only a new map will pick those up.

However ... in this particular case, all of the major mapping services still show that this bridge across the Ouse is navigable (even if you feel that it is not). So whatever information is getting around about this old bridge, it's going to hit the routing of any device.

 

[Andy_P]

I don't think the Go520 supports IQ routing (an innovation that came later), might that be a possible reason for the differing re-routing speeds between the two devices?

You should try comparing the routing speed of your OneXL to any of the new NAV3 or 4 models (Go1000 etc.) !
Thery are FAR faster, so TomTom has made a lot of improvements since the Go520.

 

[Andy_P]

Google maps shows the route over that bridge as open...
... and there are StreetView images of the bridge as having gates, but they were open and the van certainly seems to have driven over it OK.

It looks freshly painted too.

http://goo.gl/maps/5uMFT

The only warning signs on the approach is that the bridge is weak so to go dead slow.. So I don't think the TomTom is doing anything wrong.

 

[Arno]

Arno, we were trying to navigate from TQ568047 along the A27 to Rodmell. The recommended route took us via the A26 to the old bridge at Southease (TQ428053) which has not been fit to drive over for many years/decades (see this link: http://www.geograph.org.uk/photo/3431939). The turning off the A26 to the bridge was marked dead end so we turned around, went back to the A27 and drove West which is correct for an alternative route to Rodmell, but the GO520 refused to replan a route until we had reached TQ424100 in Lewes. That's my gripe.

Let's get the gripe out of the way first.
I had asked you to supply coordinates but you decided to provide grid square maps locations that are neither supported by TomTom nor Google maps, forcing me to to find those via the Internet.

You never mentioned that you had decided to use "Waypoints" (via the A26).
If no way points given, or other instructions made, TomTom will try to use the shortest route.

http://i39.tinypic.com/1430wa1.jpg

This ties in pretty much with Google map, which also selected the fastest route.

http://preview.tinyurl.com/lf8osbt

Note that neither routes over that rickety bridge.

 

[runner_bean]

Arno, apologies for any inconvenience but if you ask a UK resident for coordinates you will invariably get Ordnance Survey grid references, as that's the basis for all our consumer mapping! A pity TomTom can't use them.

The lat/long equivalents for the OS start point reference I gave are 50deg 49min 12.54sec N, 0deg 13min 36.02sec E. I think Mr Google did not give you the right translation as your route starts somewhere else altogether.

I did not use Waypoints (A26) and with the correct start point I think you will see why.

Andy_P, if you use Street View to follow more of the route you will see multiple highway authority 'Dead End' signs where you turn off the main road for the bridge route (from both ends) designed to encourage traffic to turn back. Clearly it is not a satisfactory route for general use as it is also narrow and floods and should certainly not turn up on a 'Fastest' route selection. Indeed, many vehicles would be too wide to get over the bridge. There is a lot of history behind the bridge http://en.wikipedia.org/wiki/Southease.

 

[canderson]

Arno, apologies for any inconvenience but if you ask a UK resident for coordinates you will invariably get Ordnance Survey grid references, as that's the basis for all our consumer mapping! A pity TomTom can't use them.

While I have used OS maps in the UK, the problem is that there are heaven knows how many different such schemes that have been adopted in various countries around the world since the idea of map grids began, and even within the normal lat/long scheme, dozens and dozens of different datum references. While a few handhelds are capable of managing conversion between WGS84 and these other methods for arriving at a point, the entire reason for WGS84 was to provide a universal means for identification of a point. You will find that GPS chips do not return Ordinance Survey coordinates, or old U.S. style NAD27 or even UTM coordinates or any other coordinates than WGS84. Any other datum must be computed. Sorry, but it's a bit like the U.S. still using 'imperial units' of measure like pounds and miles. You're a bit behind the times on maps, and we're behind on everything else. We all hate to give up the familiar.

 

[runner_bean]

Well actually my ten (at least) year old basic model Garmin handheld etrex GPS will give me UTM, WGS84, NAD27 in multiple varieties, Old Egyptian (!) and a host of other national coordinate formats all for the choosing. So it can't be that difficult...

 

[canderson]

If you'll look at my signature line, you'll see 4 different Garmin models, each of which is capable of exactly what you (and I) described for handhelds. The Garmin (and TomTom) automotive units do not compute alternate datum results.

This is done because it is anticipated that handheld users MAY be using real maps associated with one of those dozens and dozens of alternate means of locating a point on the earth. Since vehicles have no need of topography or other physical map features from "old" maps in most cases (those of us who off-road are another story!), only the universal WGS84 set is produced on automotive units, regardless of the manufacturer.

 

[Arno]

Today we used the GO520 to get from a rural location to a local village ten miles away, following an A road.. The recommended route ended up taking us to a river with no bridge across!

I don't know what your 6+ year old map (per dhn) recommended but v910 does not pick the A26. See attachment below.

Neither does Google http://goo.gl/maps/1ueZP

Arno, we were trying to navigate from TQ568047 along the A27 to Rodmell. The recommended route took us via the A26

See above.

turning off the A26 to the bridge was marked dead end

So is the beginning of S Downs Way off Piddinghoe Rd but, that has not stopped the Google Street View truck. http://goo.gl/maps/To28g

... the GO520 refused to replan a route until we had reached TQ424100 in Lewes. That's my gripe.

If I get a chance I will try a side by side check of my OneXL with GO520 to see when/how they behave differently.

Checking out the reaction to a change to a planned route can only be done while being physically in that location.

The bridge over the river hasn't been safely usable since the Second World War, let alone six years ago!!

In March 2011 the bridge, was safe for 2 T (4480 pounds) http://goo.gl/maps/nRbtn

Arno, apologies for any inconvenience but if you ask a UK resident for coordinates you will invariably get Ordnance Survey grid references, as that's the basis for all our consumer mapping! A pity TomTom can't use them.

Andy_P has been a super moderator for years and years on a UK site, whereas this one had been North America centric.
I will take his word for it if he say a UK resident will understand Ordnance Survey grid references when s/he reads coordinates.

The lat/long equivalents for the OS start point reference I gave are 50deg 49min 12.54sec N, 0deg 13min 36.02sec E. I think Mr Google did not give you the right translation as your route starts somewhere else altogether.

Have a look in the left margin to see what Google thinks of the coordinates given http://goo.gl/maps/ROR1m

It wasn't Mr. Google who gave the translation Google just returned UK web sites that do translations. At the time I had no reason to believe that the result was wrong. Interestingly, both Google and TomTom show the fastest route from your turn off at the A26, at the dead end sign to be via the A259 bridge over the Ouse at 14 and 13 minutes respectively. ,

 

[runner_bean]

My grateful thanks to everyone for your assistance with this issue. I will take up the status of the route over the Southease Bridge with my local Highways Authority as it is either open for traffic (in which case there should be no Dead End signs), or it is closed. The v910 map route (Google http://goo.gl/maps/1ueZP) is the one I believe should be shown as it is safe for all domestic traffic.