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.

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.

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