Having explained how much I like using my new GPS gadget for navigating I should give some more information about the practicalities, starting with how to get the maps you will need installed on such gadgets without spending a fortune.
First of all I should make it clear that I’m talking about specialist GPS (Global Positioning System) units made for cycling and/or trekking, not smartphones. Smartphones have some excellent GPS features but they lack the speed and accuracy of the specialist products. For example in a mountainous region of India my Android smartphone took around 2 minutes to work out where it was while the Garmin GPS unit found its location as soon as it was switched on. This is partly because it has a more powerful receiver for the faint radio signals from the GPS satellites and also it is able to use signals from Russian as well as US navigation satellites, I expect the smartphone was also slowed down by having to do all its other work as well, running apps and dealing with the phone network. Smartphones have quite a few other disadvantages being less rugged and waterproof and having poor battery life.
You will need to have some maps installed on a GPS unit to allow navigation but if you buy them from your GPS manufacturer it can be quite expensive. This is even more of a problem when you consider that most GPS products are not really designed for mapreading so you don’t really get the full value, for example if you were to pay £200 for the Garmin version of the 1:50k UK Ordnance survey maps, not only is this twice the price you would pay for other versions of the same maps to be read on full-size computers or tablets, but you would only be able to peer at tiny sections of the map through a small window. On top of that the Ordnance survey maps are great for cycling in the open country but not good for the kind of urban detail where navigation is most needed so you would probably need something else as well.
Luckily there is a good answer which provides very high levels of detail, is ideal for navigation and is free, but you do need to take a bit of trouble to make it work. I’m talking about Open Streetmap, the free crowd-sourced worldwide mapping project that has created very detailed and accurate maps of most developed countries and is growing across the world.
Open Streetmap, and its closely connected little sister, Open Cyclemap, provide a great resource including the ability to install maps on many Garmin GPS units like the eTrex30 and eTrex20 models that seem particularly useful for cycletouring (I won’t discuss other manufacturers products as Garmin seems to be by far the most widely used for cycling and trekking and most of the resources available are focused on Garmin products, often for the simple reason that the amateur developers involved use Garmin themselves).
As these are open-source projects run by enthusiasts rather than businesses you can’t just buy the maps and have them smoothly added to your GPS gadget, you have to learn a little and do some work yourself. I would put the level of difficulty as similar to buying travel tickets from a poorly designed website plus adding and removing photographs from a modern camera equipped with an SD card.
Many current Garmin products like the eTrex will use a separate SD card to store maps and it will be possible to install several maps on the same card (older machines only allowed one map at a time so you had to have each map on a separate card and swap them over)
You can remove the SD card from your Garmin product and plug it into an SD card slot or card reader attached to your computer. However the eTrex also plugs directly into a computer’s usb socket and, on my Windows 8 PC, it waits a bit then displays two drive windows, one showing the contents of the unit itself and the other showing what’s on the SD card. You can drag files on and off each of these and create folders etc just like a normal hard disk or USB stick.
Map files on Garmin are called .img files and they live in a folder called “Garmin” on the SD card. So if you have a suitable Garmin .img file in your computer and want to add to your GPS, just make sure it has a different name from any other .img files already there and drag it into the Garmin folder. That part is normal computer management stuff and if you are not sure about it any experienced computer user should be able to help you.
But where do you get your .img files from in the first place? If you go to Open Sreetmap (OSM) or Open Cyclemap (OCM) there is information available about websites where you can download up to date maps for Garmin but as this is all run by enthusiasts it’s not long before you find yourself wrestling with jargon and not all the resources are really useful. I had to do quite a lot of trial and error to find something that works. If your needs are similar to mine then you may be able to follow my plan. If you need something different (eg North American maps) I hope my experience will help you make good progress in your own investigations.
There are two websites that seem to provide particularly good resources. If you want UK maps the Talkytoaster site run by Martin Overton, a computer professional who is also an experienced hiker, provides a good service although the options that Martin offers need studying, especially if you want to avoid clashes between different maps installed in your Garmin. Arguably Martin is providing more choice than most people need but this is partly because he’s pushing at the boundaries of what can be done, seeking to improve the cartographic quality/usefulness of his maps.
For the past few weeks I’ve been using Martin’s topographic “routable” Garmin maps and found them excellent for UK navigation once I had worked out which versions to install. I have his British Isles map without contours and his OS-style British Isles with contours both installed (you can only have one version with contours and the other one will borrow the contour data from its sibling, having two with contours of the same area causes the GPS unit to crash).
However there’s a bit of a problem as I’ve mentioned in my previous post since the pink line that marks the route you are following on the eTrex sometimes clashes with red or orange coloured roads on the map and is hard to read, especially in poor light. This may not be an issue for walkers but cyclists will be following roads and will need to see their route by just glancing down at their GPS unit, possibly wearing dark glasses if it’s a bright day (I have Reactolite lenses).
Garmin doesn’t seem to allow changes to the colour of that pink line so I’ve been looking for an alternative map which might allow the pink to stand out. At the same time we are planning a trip to France so I needed some maps for that, Talkytoaster is just UK.
I tried a few other download sites that provide Garmin versions of OSM maps but cartographically they were weak and not really usable, eg roads shown as thin lines or too much background colour. However I’ve now settled on the Open Fietsmap website (Netherlands: Fiets=Bicycle). OFM provides Garmin maps for all areas of Europe so I downloaded their map of Northern France/Benelux and also their UK/Ireland map. They seems to be “cleaner” than the Talkytoaster maps with less colour and slightly narrower roads, all of which seems to make it easier to read on the GPS and easier to see the pink navigation line.
If you are outside Europe, OFM also has a page where you can download Garmin maps for any area of the world not covered by their “packaged” maps, by selected grid squares from a world map. This is a bit more complicated so you may need to be more alert to use it, also the maps generated all have the same generic name when they appear on your Garmin (that’s the name of the map which you can’t easily change, not the filename which you can control) so it’s rather tricky if you have more than one of those particular downloads to choose from, I guess it’s not a problem to just have them all activated since they don’t overlap.
So you can find free detailed maps online, they are particularly suited for cycling, and you can download them to use on a Garmin GPS unit if you have a little basic computer knowledge. It’s worth remembering that OSM and OCM are being updated constantly by thousands of contributors around the world (I’m planning to add the data from our Indian trip as we went along quite a few unmapped roads) so you’ll need to download a fresh version every few months.
Also the site owners who do this work of packaging OSM maps for Garmin are enthusiastic amateurs doing it because they believe in the value of open source mapping. It really helps them to carry on with this if we take the trouble to make a donation to help their efforts, most sites will have a PayPal donate button that allows you to give them some money (eg $10 or €10 as thanks and to show you respect what they are doing for all of us).
Finally, if you are unclear about the difference between OSM and OCM (or OFM for that matter) it’s not a big issue. Open Streetmap is the big map, a geographical information system to be precise, that stores all the map data collected by volunteer contributors, including information about cycle routes and cycle facilities. Open Cyclemap/Open Fietsmap uses that data to present specialist versions of OSM tailored to the needs of cyclists, including showing official cycle routes and contour lines. It’s interesting to look at the Open Cyclemap view of the whole of Europe because the volume of official cycle routes in each country gives an immediate picture of how much priority the authorities in different countries give to cycling.
Next – Creating Routes (coming soon)