Topo50 anomolies

The last couple of days has seen some unusual news whereby the chief guide of the Manawatu Tramping and Skiing Club has been pointing out that some of the new Topo50 maps are wrong, following a trip they had in the Ruahines. In particular, the maps included incorrectly marked or missing tracks, and such.

The story was first penned in The Manawatu Standard, and it’s since been picked up by Morning Report on National Radio (streaming available in your choice of [Windows Media Player], [MP3] or [Ogg Vorbis] depending on your preference).

I don’t know what the errors are, and perhaps they’re especially bad. On the other hand, I wonder if the fact that the Topo50 series maps have errors means that they’re any worse than the 260 series. It’s hard to tell for sure without more information. It’s in everyone’s interests to have maps that are correct, but it’s common for NZ topo maps to have errors here and there, and sometimes it’s just necessary to accept this. The only way to really be sure about a region, short of asking someone trustworthy or going out with them, is to be prepared for anything, look at the landscape, be in a frame of mind to change plans if necessary and then learn about an area from experience.

I vaguely remember something from a while back (but can’t find a reference) in preparing Topo50, whereby LINZ was convinced to include older tracks and emergency routes that had been removed from some of the more recent 260 series maps. Prior to that there had been discussions about removing even more tracks from the map, but there was an outcry to the best of my recollection. We discussed this in our tramping triangle at work today, and someone suggested that perhaps the false or missing tracks are old tracks that were shown on older maps of the region, and have since been put back in the new Topo50 series.

The strength of topo maps (at least in New Zealand) has never really been about tracks, it’s terrain and topography. Keeping track of tracks and routes is a difficult thing to do, because they’re often difficult to see from the air, especially under trees. They change frequently, often without any official influence. People will sometimes go out expecting to find a good track or poled route based on a map, and find something quite different, but this isn’t something unusual with earlier maps and I’m not sure why it should be different with Topo50 maps. If you happen to go out expecting to find a track, but there isn’t a track, then clearly the map’s wrong. All it does it change the rules a little. it may make sense to continue depending on things like circumstances, experience, conditions and knowledge of the rest of the environment. If you happen to be not terribly confident with continuing, though, the obvious thing to do is something different. In other words, do what it takes to get back into whatever your comfort zone happens to be.

This may mean returning to where there was a track, and going back the way you came to return another day, or stopping and finding a safe place to camp for the night (unless you’re a victim of The Hut Fallacy) to consider things properly with a clear head in the morning. I guess this whole philosophy implies some kind of good judgement, which isn’t always present and not because people are irresponsible. Sometimes people just have bad days, or groups make strange decisions that individuals might never make alone. I don’t know exactly what to do about this because there have forever been people getting into trouble for these reasons and most likely there will be in the future, irrespective of improvements to track details on maps.

Some good news with the switch to Topo50 is that changes and updates are likely to get into the mapping system much more rapidly. With its overhaul of mapping systems, LINZ also completely changed the way it publishes maps. Pre-processing is now all done in-house, such that LINZ can now run off a new map edition soon after updating their system. It won’t take existing maps with errors off the shelves, but it could mean that new orders from retailers sent to replace them have corrections. Previously, new editions only came out every decade or so, and each map had to be manually re-plotted and carefully examined (which is why some maps had inconsistent shadings), and was probably pre-printed in large numbers.

Hopefully the ability to correct maps more quickly will also lead to more people submitting corrections. There are enough people out tramping with good GPS devices these days that getting accurate positions of the tracks is becoming much easier, as long as you can trust the person providing the data, and trusting the data may be the most difficult part. For instance, I’m now trying to digitally track every time I go out for a walk, but just because my GPS has been somewhere doesn’t mean it’s a track. My GPS stops and starts, it takes short-cuts, it ventures off-track to look at interesting things, and sometimes it just leaves the track completely because there is no formed track to wherever my GPS wants to go. When I return, I don’t always have a reliable memory of exactly when I was and wasn’t on a track, or the standard of that track, but then that’s not my main motivation for digitally recording where I’ve been. I guess time will tell.

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