I bought Sophie a TomTom One GPS unit for Christmas 2006 to help her navigate when she had to go somewhere on her own.

It works fine if you just want to get in the car and tell it to get you from where you are now to a known destination. You type in the postcode, wait a few seconds, and then off you go.

There are two areas where it doesn’t work so well, 1) if you want to plan a journey in advance that takes a route that you prefer, passing through specific ‘way-points’ on the way, and 2) showing you details and statistics of a journey that you have just taken.

Sophie recently had to take her mother to a funeral in East London so I manually created an Itinerary on the TomTom that took her there and back via the M25 and Dartford Tunnel. This was the most straightforward, if not direct, route but Sophie still managed to get a bit lost, going through the Dartford Tunnel a few more times than was absolutely necessary, and later decided to come home through central London rather than the M25. I thought that it would have been great if I could have looked at the route that she actually took when she got back home.

I set about finding solutions to these failings.

Planning a route in advance

You can do this on the TomTom using an Itinerary, but it is a bit of a pain as you have to do it all on the small screen which is fiddly and takes a long time.

I found a piece of software called Tyre. This lets you plan your route using Google Maps or Google Earth. It then creates an Itinerary file which you can load in to the ‘Itn’ folder on your TomTom and load as an Itinerary. You can save multiple Itinerary files to cater for all sorts of scenarios.

Basically it does what is says on the tin. Download it. Use it to plan a route, upload the file to your TomTom, and off you go. It couldn’t be simpler.

How to see where you actually went

Although you can create Itineraries on the TomTom without any additional software if you want to, there is no standard way of looking at past information showing a journey you have just taken, how long it took, etc.

I found a great piece of software called Event_Logger. This utilises the fact that the TomTom is actually a small computer running the Linux operating system and uses a standard GPS chipset. It can be modified to extract GPS information on a regular basis and write this to a file on the TomTom’s own internal storage, which can then be viewed at a later date, using a separate piece of software, to show your previous journeys in great detail using Google Maps or in a text format.

Start by downloading the software from the above site. There isn’t actually a link to download the software from the web site at the moment, so you can either make a donation to Amacri and then ask him for the link or, those of you that know me, can ask me and I will send it to you.

It is a simple matter to copy it on to the TomTom and you then immediately see some extra options appear from the main menu. The key factor is that there is now a new task running on the TomTom that queries the GPS location details every 5 seconds (configurable) and writes this information out to a file in the ‘Itn’ folder. Separate files are written out each time you turn the TomTom off and on, so you can see journey info going back a long time. These files are automatically zipped in to an archive file on a regular basis to save space. It’s all very sophisticated.

When you have finished your journey connect the TomTom to a PC and view the trip information directly from the TomTom. This only works using Internet Explorer, so tough luck to anyone using Mac or Linux.

Go to the ‘Itn’ folder and open the relevant .XML file using Internet Explorer. If you want to copy the file on to your PC then you will also need to copy the ‘gpx.xsl’ file in to the same directory. A friend of mine has had trouble opening the XML file on his PC. I think this is related to his IE security settings. I have my IE security set to default values, with the Internet Zone set to Medium High, and the Local Zone set to Medium Low.

This shows how the route is displayed using Google Maps, You can click on specific points to be taken to the detailed info. You can select two points on your journey and get stats showing time and distance between them. If you put the cursor on the right hand border of the map a box pops up showing various options.

This shows the overall route summary.

This shows details of individual points.

When I first tested it I found that my route files had some bad records, where the Longitide value was set to ‘0.000’. This obviously caused the route map, and statistics, to be inaccurate. I reported this to Amacri and he immediately sent me an update which fixed the problem. This might be specific to my model of TomTom One so someone else might not experience it. I can send you the update if needed.

I noticed that the statistics don’t show any altitude data. It turns out that Event_logger works in ‘snap to road’ mode by default where it only stores data for 2 Dimensions which are mapped on to Google Maps. You can turn on ‘off-road’ mode where it will store 3D data. I haven’t tried this yet so I’ll let you know how it works later.

There are many more options available but the best thing to do is to read the documentation on the web site to get the full picture.


Both of these bits of software are great examples of what a dedicated individual can do to help the community as a whole.

The combination of the two turn the TomTom from a simple GPS route planner in to a more sophisticated device that can take you where you want to go using a route of your choice and then tell you where you actually went and how you got there.

I recommend them both.

Useful links

You can see all my other TomTom related bookmarks here.

A quick note to say that Event_Logger has been upgraded to 8.0.

You can download it from here.