GPS navigation on George and Jean's Brittany 2008 Tandem Tour

Keywords: open source GPS, cycle route planning, Garmin Edge 205/305/605/705, Garmin ForeRunner

Commenting facility added January 2009. Please please consider adding your comments to this page.

Overview

I have been fighting with online mapping systems and GPS devices for 2-3 years with the aim of using a GPS for navigation on our annual cycle tours. Until this year, none of them has come near to meeting our needs and we have fallen back on paper-based maps with daily routes pre-planned and traced with a highlighter.

I've now finally found a system that meets almost all our needs and I'm writing it up here in case it is of interest to others.

It is based not only on a specific GPS but relies also on the use of Google Maps for route planning as well as several web-based open software tools for file conversion.

Our requirements are:

A handlebar-mounted GPS that is robust, waterproof and has the battery capacity for > 8 hours of use and the memory capacity to store all the maps, planned routes and route logs for at least two weeks' of cycle touring.
The GPS needs to show a legible map overlaid with a route in the context of the adjacent roads and geographic features, preferably including contours and heights.
The ability to plan routes that follow exactly the roads that we want to ride and pass through all the places we want to visit.
Logging of the routes actually ridden, with the intention of displaying them in Google maps on return and/or using them for 'geotagging' the photographs taken throughout the tour.

We chose a Garmin Edge 605 bicycle-specific GPS, but we used almost none of the PC/Mac software that Garmin supply for use with it. Nor did we use the GPS's built-in route planning feature - I don't think it can provide the type of routing that is conducive to enjoyable cycle touring.

Instead we used Google Maps 'Get directions' with the 'Walking' option to generate each day's route. The basic routes generated by Google's router were heavily modified interactively using Google's brilliant 'dynamic routing' feature which allows any part of the route to be dragged to follow any road and/or pass through any point on the map. The route 'snaps onto' roads in a very impressive and intuitive manner. It takes us only a few minutes to create a route for each day following the most attractive-looking roads and passing through exactly the places we want to visit.

The colour screen of the GPS renders whatever pre-loaded maps it contains in a legible manner, but the screen's small size is inadequate for getting an overview of the day's route for planning stops or making changes to the route. Our solution to this was to carry the relevant pages from a Michelin 1:200,000 Road Atlas which were displayed on top of a handlebar bag.

Equipment and Maps

Garmin Edge 605 Bicycle GPS (500MB internal memory, 1 GB SD card). Battery life > 15 hours.
Digital topographic maps installed in the Garmin covering the area(s) we toured. We used the IGN TOP25 digital topographic map for our tour of Brittany. It shows the tiniest roads, many tracks and footpaths and has contour lines at 50m intervals.

You can obtain topographic maps for the UK, France and some other European countries from Garmin or their retailers, either pre-installed on SD cards, supplied on CD/DVD or downloadable. In the latter case you have to use Garmin's not-very-intuitive tools to install the maps for the areas you will visit. I installed them onto a separately-purchased blank 1 GB SD card. This card provides adequate space to install maps for all the areas we are likely to visit in the foreseeable future.

It's worth noting that OpenStreetMap is becoming a useful source of free mapping that has been ported to the Garmin, at least for some areas. Caveat: I have not yet tried these on my Edge 605. If you have, please report on it in the comments to this page.

Making our daily routes and installing them in the Garmin

1. Use Google maps 'get directions' with the 'walking' option and then employ 'dynamic routing' to make a route for each day's ride that follows attractive routes on the smallest available roads. Avoiding hills is another possible aim, but it requires a map with contours or some other means of profiling the route. ~~Google Maps does not yet provide that~~. Google Maps Terrain view now includes contours. I'm looking forward to using that on our next tour.

2. Extract the Google Maps route and convert it to a GPX file using the script described at:

http://www.bikely.com/forum/discussion/1377/google-maps-new-dynamic-routing-good-for-bicycle-routes/

which is aimed at Bikely users, but I got good results using it to make files for the Garmin. I used the 'Bikely GPX option'. I haven't tried the 'Garmin Course' option. But I did use the 'Cue Sheet' feature to get printed Cue sheets with details of all the turns. These were used occasionally along the way to clarify things.

Another relevant tool for this conversion is described at:

http://www.elsewhere.org/journal/gmaptogpx/

You have to copy and paste the GPX text produced by either of these scripts from a browser window into a text editor, then save it with a meaningful name and a .gpx postfix so you'll be able to find it on the Garmin.

3. Copy all the GPX files into the Garmin/GPX folder in the Garmin's internal memory or the folder with the same name on the SD card. (The GPS can use them in either place).

4. To navigate using one of the routes, use the Where To?>Saved Rides menu on the Garmin to select a route from those you will see listed. When you return to the GPS map view you will see a pink/mauve coloured line showing your route overlaid on the map. When you are following the route you will get a prompt on the screen for every change of direction.

If you diverge from the route, the Garmin will continue to track your position on the map and log your route (if the logging feature is turned on, see below). When you rejoin the planned route the directional prompts will resume.

Logging routes and converting log files for display on a Google map

The Garmin does a good job of making a log of each day's ride. Just press the 'start/stop' button before you set off. The log will be terminated when you turn the Garmin off, or when you use the 'reset' button. The logs are stored in the Garmin's internal memory in the folder Garmin/History with files named by the date time when they started. E.g. '2008-09-21-07-33-37.tcx'.
The .tcx file format used for logs is a Garmin-proprietary XML dialect intended for use with the Garmin Training Center software. But it is possible to convert tcx files to the KML format, which can be imported into Google Maps and Google Earth. I found the most reliable and effective converter is the online one offered at: GPSies.com. If you plan to import the KML tracks into Google Maps it's a good idea to use the converter's Track simplification option and to reduce the number of points to about 200-400 per day using the slider on the converter page.
If you want to see a height profile of the route and various statistics such as total distance, total climbing, etc., load the GPX file you have generated back into GPSies.com's track library (you have to register and then use the Upload page). This method for getting statistics and profiles will work with any GPX file, whether a planned route or a log of ridden route.

We obtained this excellent record of our recent tour of Brittany using the above method.

Drawbacks

Topographic maps don't support route planning on the Garmin itself. Any routes planned while on tour using the Garmin will be based only on the built-in Base Map of Europe which includes major roads only which are generally unsuitable for cycling. This was problem for us when we hadn't planned our routes through two cities in sufficient detail. We made the Garmin plan routes for us on the fly, but the results were neither short nor quiet.

It may be possible overcome this problem by installing the Garmin City Navigator Europe maps in addition to the topographic maps. But we didn't do that because we prefer the more open and flexible approach to route finding based on pre-planned routes made using Google Maps.

Conclusion

This was the first of the 20 or so cycle tours we have completed on which we never lost our way nor had to stop to work out where we were. The Garmin Edge 605 deserves a large chunk of credit for this - it's a very well engineered device with impressive GPS positioning performance.

We were less impressed with Garmin's supporting software and we were very pleased to find that the Internet community has supported digital mapping to such an extent that made it possible to follow the more open approach described above. We're very grateful to the Google Maps team and to the developers of the other software tools mentioned above.

George Coulouris, October 2008, revised January 2009, May 2009

Comments

Commenting facility added January 2009. Please please consider adding comments to this page.