Of Mapping, Routing, Paper & Screens

I have always loved maps and charts.  A good map is a gateway to a world of adventure and story. Maps have always meant paper; the way they fold and can be annotated. The way they can be laid out to show the whole territory and aligned to bearing and direction. Lines plotted and position found. The way you can zoom in to the area of interest and the finest detail. 

So when on a long ride I’ve always taken along the relevant paper maps. OS 1:50,000 for long distances (or Michelin yellows in Europe) or sometimes the 1:25,000 for finer detail. They lived in a drawer in the sideboard gradually going out of date. I can remember at least two occasions when new roads slicing across the countryside since the map I was reusing was printed left me hopelessly confused on the ground.

A few years back I got a GPS device (Garmin eTrex Vista HCx) and mounted it on my bike. Great for logging time speed and distance and providing a tracklog to download and overlay on an electronic map. The screen is colour, but tiny. OK for the close in detail, for example in towns to find the night’s digs, but hopeless for the overview and route planning, so the paper maps still came too.

Getting good maps (velomap open source mapping) onto the memory card in the Garmin is more than a hassle, especially since the limited file size means often having to prune back the areas covered. I’ve fallen off the edge of the loaded maps more than once, although it still works fine for logging and direction finding.

This year I have acquired an android 7″ tablet to use as a primary map with OpenSourceMaps and been experimenting with it on the DMX to Exeter ride.

This particular tablet also has a data pay-as-you-go sim card so I was also able to use google maps for online use. Of course I still had the eTrex as well.

Firstly the tablet is ok for route planning whatever map source you are using. It is not as good as a paper map because it is physically much smaller and when you zoom out you loose a lot of detail. It can be tricky zooming and panning around to keep track of what you are looking at – especially whilst on the road.

With the offline OSM maps it takes longer to route find than with google (obvious really as it only has a fraction of google’s processing power) but it does get there within a minute. Ok if you are setting it up the night before.

Both OSM and Google offer a “bike” routing option, and in practice both managed to make mistakes. OSM one time sent me along a footpath with stiles – not event suitable for mountain bikers. Google on the other hand insisted that a muddy rutted track across the Somerset levels was a paved road.

Also both Google and OSM seemed to be prone to getting lazy towards the end of an 80km cycle route – typically opting to send me down a main road when there was a perfectly reasonable nearby minor road alternative to the destination (yes “avoid main roads” was turned on as an option).

I found the automatic recalculation of route when you drifted off a bit annoying – maybe it can be turned off, but I couldn’t find out how. Often I simply wanted to get back on to the originally agreed route after a detour to look at something interesting, not take some alternative – let along have to wait while the offline mapping recalculated the route.

I was carrying the tablet in the top of my handlebar bag and found that I was often opening the lid to take a look, it almost becomes compulsive. One problem with this is that things are prone to bouncing out of the bar-bag when the lid is open and the road a bit bumpy. For future trips I plan to have it fixed to the top outside of the lid in a waterproof pouch.

Naturally the tablet screen is not so good in sunshine – I’ve never had a problem reading the tiny eTrex screen whatever the light – and also the battery in the tablet is fading by the end of a six hour ride, which of course tends to be when you really need it.

When you know roughly where you are going the little eTrex Vista screen isn’t too bad – it is hopeless for the whole day’s ride. It is also incapable of calculating routes more than a few km long in less than an hour as it is very low powered – which does at least mean it has decent battery life.

I think the answer next time – R2W is to see if I can upload routes from the tablet to the eTrex. That’ll be a bit of a technical challenge…