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How TomTom make maps - Part 5: Map Changes

Part 1 : Map Geometry
Part 2 : MapShare
Part 3 : IQ Routes
Part 4 : HD Traffic
Part 5 : Map Changes

In the previous articles in this series we have seen how TomTom source their data, how the community provides input to improve the maps, how probes have been used to analyse the data, and how traffic information is collected. This final part of the series looks at how all these pieces are put together to manage changes in the mapping data.

 

As we have mentioned in previous articles there are many data items captured and entered into the main TomTom database. Of course collecting the data is just a small part of the process. With hundreds of billions of bits of data it is impossible to process each and every one as an individual item. This is where the back end systems come into play.

 

The TomTom maps are maintained by an online system known as Cartopia. Cartopia is a browser based editing system that allows a map editor to view many different items of data related to the area that they are working on. It also allows changes to be made and committed to the master database for inclusion in the Map Share updates or the next full map data release.

 

 

The servers consolidate the input data into a number of different overlays. You could consider this to be analogous to an old cartoon where the scene is made up from different transparent layers enabling the user to see through the layers to obtain the full image. Here we are not talking about pictures, but different types of data rendered over a base map to allow the map editor to see what the 'real world' view of the data is.

 

The vast volumes of data would make it impossible to depict each piece of information individually so to overcome this various data elements are combined into what is called a heat map. This is where the individual probe reports for things such as speed or direction of travel are combined to provide different coloured lines which can overlay the road lines. This is then combined with more static information such as digital imagery etc to produce the map overlays.

 

Users of smartphones and iPhones will already be familiar with this concept to a certain extent with the mapping applications able to show aerial photography, digital road maps, and traffic information. These layers can be omitted, or combined into hybrid views of the information. This is the core concept of data display on Cartopia, but this is taken very much further.



In the example video I got together with a TomTom mapping editor to look at a major road improvement scheme near where I live. In essence the Department of Transport are reverting a multi-roundabout system into a large roundabout with a bypass, and an interesting contra flowing junction. This is altogether quite a complex change, but looking at the various elements and overlays of Cartopia we were able to see exactly what the traffic flows were around the new junction and it would have been possible to implement this in the master map database without even visiting the location.

 

This was achieved through the use of the probe data, combined, to a lesser extent, with aerial imagery from the early part of the project. The heat maps from the probe data showed that the movement around the roundabout had stopped being in both directions and was now in a single direction, with the exception of one area where this strange contra flow junction had been implemented. All of this is clearly shown on the video as we switched the layers to see what the current state of the road layout was. In fact the only thing that we were unable to do remotely, and required a visit from a mapping van, was determine the road signage.

 

This is all well and good, but (and there is always a but) although we were able to identify the changes TomTom did not include them in a daily Map Share update so we will have to wait until the next full map release to take advantage of the changes. This is where there is room for improvement, the technology exists to make at least some of the basic modifications, but they did not see the need to implement them. In fact as you can see on the video I made the changes to the existing map in Map Share myself, but unfortunately these have not been distributed to other users. I can understand the difficulty in adding the bypass which is effectively a new road, but flow changes to existing roads should not be a problem, indeed that was one of the core arguments for Map Share in the first place.



 

Conclusion:

 

Clearly TomTom have come a long way in devising methods and mechanisms to create and update their mapping products introducing innovative tracing mechanisms and community initiatives. There is also clearly a long way to go still. The mapping utopia would be to have dynamic maps that can be incrementally updated thus ensuring that there is minimal delay between a change being made in the real world and a modification being made to your map. This does require a further leap in the mapping technology as currently changes can be made to existing roads, but new roads cannot be added.

 

Once the infrastructure is in place for this new mapping format and capabilities the driving forces initiating the changes will need to be refined and improved allowing for easier and faster identification of changes and the processing of the massive daily input. This is, of course, easy for me to say, but far more difficult to implement, and will remain the challenge for the TomTom mapping group over the next few years.

 

The other issue is how TomTom will fund these changes. They are faced with the unenviable challenge of users expecting free mapping, but of impeccable quality. Creating and maintaining maps is not cheap so some revenue generation that is both acceptable to the userbase and to TomTom corporate accountants must be found to ensure that we continue to receive maps in the future.

 

At PocketGPSWorld.com we have been processing just a small part of the data that TomTom does and understand some of the challenges that TomTom face in pushing the map technology forwards.

 


References

Manufacturers Web site http://www.TomTom.com
Pocket GPS Contributor

Mike Barrett

   
Forum Comments:

 

Comments
Posted by dorsetwurzel on Thu Aug 23, 2012 4:41 pm Reply with quote

Very interesting article. Looking forward to the next one. Very Happy


TomTom XL IQ routes Europe App 9.401 Map W Europe v880.3810. iPhone 4s 32Gb with PGPSW CamerAlert, Tomtom UK & ROI v1.10 with HD Traffic. Tomtom car kit. iPad 64Gb 4G + GPS
@dorsetwurzel on twitter

If I'm not here, I'm out Geocaching

 
Posted by jonrome on Fri Aug 24, 2012 8:21 am Reply with quote

It would be great if someone could produce a way to convert present day maps to th run on the thousands of Alpine systems installed by Jaguar up to the the late 2000s. Absolutely no support.
A disgraceful state of affairs for a company like Jaguar who appear to be proud of their heritage but really only want to sell you a new car.


 
Posted by Surfing_spider on Fri Aug 24, 2012 9:35 am Reply with quote

Great Article. I really like getting to know the details of exactly how these systems work.

What I really want to know is why the junction priorities are wrong so often. i.e. when you are driving along a road and it tells you to take a left turn but this is just a natural continuation of the road. There does not seam to be a part of mapshare that allows you to correct this. I am eager to help fix these issues but can't.


 
Posted by Daggers on Fri Aug 24, 2012 9:52 am Reply with quote

Surfing_spider Wrote:
What I really want to know is why the junction priorities are wrong so often. i.e. when you are driving along a road and it tells you to take a left turn but this is just a natural continuation of the road. There does not seam to be a part of mapshare that allows you to correct this. I am eager to help fix these issues but can't.

I'm with you on this one - you can just about work it out if it tells you to turn left when the only obvious straight-on route takes you up a farm track, but if you're in a built up area and told "in 400 yards, take the 3rd left" it gets a whole lot more confusing.


TomTom Go 550 Live
App 9.510, UK & ROI Map v 935.5753

 
Posted by cbrown7 on Fri Aug 24, 2012 2:05 pm Reply with quote

I'm with Surfing_spider and Daggers on this one. Plus, why on UK back (B) roads do Tom Tom's often not alert you at all to cross roads you have to give way at? I know it is up to the driver to interpret the road and drive to the conditions etc. but you do tend to get lulled into a false sense of security if you have no warnings of impending actions.

I can't believe this is down to priority changes as most of these roads have been there for years, with little traffic, so why would they change?

Great article by the way.


 
Posted by pillboxman on Fri Aug 24, 2012 2:52 pm Reply with quote

Great article. Thanks.

My guess would be that the 8/10 meter 'spots' on the roads is the reason that the on screen mapping is so much better on a TT than a Garmin.

As well as speed cameras I use my TT to help me drive more economically. I can see the road ahead and slow down or speed up depending on the bends in the road. This saves tire wear, fuel and brake pads!

Oh, and it's great at navigating as well. Laughing


 
Posted by MikeB on Fri Aug 24, 2012 4:44 pm Reply with quote

pillboxman Wrote:
... My guess would be that the 8/10 meter 'spots' on the roads is the reason that the on screen mapping is so much better on a TT than a Garmin. ...
The 8 or 10 metre bits only refer to the imaging so a picture is taken and geo-referenced at those intervals.

Typically there will be far less points in the map as they are simply not required. A road is normally pretty straight for long distances so additional points are only required at junctions.


Mike Barrett
Editor, PocketGPSWorld.com
Follow PocketGPSWorld via our Twitter feeds: Darren and Mike.

 
Posted by Stormtracker on Fri Aug 24, 2012 5:58 pm Reply with quote

If TomTom go out-and-about in their "car derived van" doing some of the mapping, then surely they can create a section in the menu for vehicle types: Such as-

Are you driving a Car, Large Goods Vehicle etc. So it can route narrow or wide roads only.

Because I am sick and tired of approaching an "Unnamed Road", or "B" road slowing down and thinking, yes this is wide enough for me and another vehicle to pass without problems. To get half way down this road, to find that it narrows alot and that my Large Goods Vehicle is actually wider than the road and I am stuck facing an oncoming vehicle - obviously using a TomTom too.

and another thing - "Turn-a-round when possible". lmao, you try turning round a 7.5tonne flatbed truck on an urban road.

Sometimes, I just want to put my "TT820go live" under the front wheels and say Route This.

Excellent article by the way. However, if TomTom use all this technology, why are their maps still upto 1 year out of date?


 
Posted by pillboxman on Fri Aug 24, 2012 6:26 pm Reply with quote

Stormtracker Wrote:
If TomTom go out-and-about in their "car derived van" doing some of the mapping, then surely they can create a section in the menu for vehicle types: Such as-

Are you driving a Car, Large Goods Vehicle etc. So it can route narrow or wide roads only.

Because I am sick and tired of approaching an "Unnamed Road", or "B" road slowing down and thinking, yes this is wide enough for me and another vehicle to pass without problems. To get half way down this road, to find that it narrows alot and that my Large Goods Vehicle is actually wider than the road and I am stuck facing an oncoming vehicle - obviously using a TomTom too.

and another thing - "Turn-a-round when possible". lmao, you try turning round a 7.5tonne flatbed truck on an urban road.

Sometimes, I just want to put my "TT820go live" under the front wheels and say Route This.

Excellent article by the way. However, if TomTom use all this technology, why are their maps still upto 1 year out of date?


Have you considered purchasing one of the HGV PNV's? You can put it against your tax.


 
Posted by DennisN on Fri Aug 24, 2012 9:51 pm Reply with quote

cbrown7 Wrote:
I'm with Surfing_spider and Daggers on this one.

[snip]

I can't believe this is down to priority changes as most of these roads have been there for years, with little traffic, so why would they change?

Great article by the way.

The reason for all these funny instructions is TomTom have reduced the details on some "roads", presumably for space constraints on mapping. Compare these two screendumps taken from two devices, running side by side, but with different map versions - the first one is an older map, second a more recent one.





Now for side roads.. Here are two views of the same spot. The first picture is from my ancient map (2006-ish?), the second and third are from the current map which instructs me to turn left or right at this corner. Notice that in the older map, the offshoot "roads" used to have the purple dots which denote non-navigable roads. I regularly get exactly the same from laybys - instructed to keep right (and not go into the layby). No doubt the savings allow TomTom to add value, like facebook and twitter links! And avoid the need to increase the size of the device's internal storage. A few months ago, in North Devon, I was instructed to turn right when the straight ahead alternative was over a stile and along a green lane filled with weeds four feet high!






Dennis

I'm getting a cat flap for my whippet

 
Posted by Stormtracker on Fri Aug 24, 2012 11:37 pm Reply with quote

[quote="pillboxman

Have you considered purchasing one of the HGV PNV's? You can put it against your tax.[/quote]

Hi Pillboxman,

I only bought this TT820 back in April this year, as I was using it mainly for my car and occasional driving when one of the drivers was on-leave/off-sick at work but in the past couple of months, I am now one of the permanent drivers and I have found how useful my TT really is. TT's PNV's are only good for Car Navigation and (expletive) for Truck use.

Yes, I have been looking at a Snooper Truckmate and I may have to purchase one of these before I lose my insanity or drive over my TT - which ever comes first Laughing Out Loud.


 
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