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DoC Track Time Calculation Nightmares

IMG_9254 [1]
HA HA HA HA HA HA HA! Sometimes it’s
just fun to leave the sign there.

I found it really interesting to read Alistair Hall’s article in Wilderness Magazine [2], which describes a recent Official Information Act Request to the Department of Conservation regarding how it estimates the track walking times that are typically advised on signs around the place. If you’ve spent any amount of time in New Zealand’s conservation estate track network, it’s likely you’ve experienced inconsistencies in the accuracy of such times. It shouldn’t really be unexpected, given that every sign presents a single time whilst people clearly walk at different rates. No stated time can be correct for everyone.

Most interesting for me from the article, I think, was not the revelation that estimated times aren’t pulled out of thin air so much as the mish-mash variety of different methods that various conservancies use. Some conservancies have slow staff walk the track and time it at a leisurely pace. In the Marlborough Souds, a fit staff member walk the tracks, then times would be weighed slightly downwards… unless they were shorter walks in which case they’d find a staff member near retirement. (No mention of how fast this older person might be—many “physically mature” people can still crack it through the outdoors pretty fast.)

Some conservancies make informal guesses and then consult staff from their experiences. Times on signs around Egmont National Park were estimated by paying a contractor to walk every track in the park and time distances between signposts, and the times were then adjusted depending on the track type. Conservancies throughout the central North Island use a formula based on the Naismith Rule of thumb [3], basically looking at a map and taking hill ascents into account, and then weighting the results further for the kind of track and expected type of visitor.

None of them, however, allow for variation in the type of person who might be walking on a track. They all produce a single time for the signpost next to any stretch of track, and typically don’t indicate who it’s for. Irrespective of how much calculation occurs for variations in the track, an assumption is always made about the visitor. It might be an assumption that people are very fit, or alternatively that the visitor could as easily be pushing a baby stroller, but the signs don’t say.

IMG_9115 [4]
A boardwalk-happy contractor was hired especially
to help calculate times in Egmont National Park.

Reading the article provoked earlier thoughts, because for some time I’ve introspectively assumed that there’s not a linear relationship between something like “fitness” and times. It’s not always possible to just take a measurement for one person and multiply it by a constant for yourself, because you might adapt differently from that person depending on the condition. For example, I could name several people for whom I walk roughly the same speed on the flat, but as soon as we’re going up-hill, I move faster. If a DoC sign refers to a track that turns out to be all flat, we’d need to multiplying by the same constant, but if it turns out that it’s partly up-hill and partly flat, the constants will be different for part of the track and not the rest of it. Problematically, it’s not clear how much of each they should be different without knowing how much is flat and how much is up-hill.

Even if impractical, it could be a fun experiment to have sign-posts that don’t merely guess at a time, but indicate the type of track or route and how much of it there is. If I knew there would be “5 units” of the sort of hard flat track on which you’re only slowed when trapped behind a platoon of people with giant umbrellas walking their dogs, and “12 units” of a steep and slippery up-hill scramble, I could apply my own personal multipliers to each of those sections to guestimate my own personal time. Anyone else could do the same, but with their own multipliers.

I’ve run into this same sort of issue recently when trying to design the board and player characteristics for the Tararua Board Game experiment [5] (with which I’m being eternally lazy), and how easily players could move around the board, but I’m starting to wonder if it’s not worth the bother in favour of keeping the rules simple.

I’m sure the whole thing could get complexified with many different variations of tracks and routes and rivers, adjustments for weather issues, and so on, and then there are things that can’t necessarily go onto signs at all such as a track’s current short-term condition. That said, I do still wonder if, with the right selection of variations, there could be a more practical and flexible way of estimating track times for wildly different kinds of people and groups.

There are also other approaches. When I mentioned this on twitter, Simon McAuliffe [6] promptly responded to point out [7] that he’s written his own personal GIS software that calculates times, optimal routes, required energy, and which can be tuned to individual people or groups with some empirical GPS input from their experiences. (Show off! :-P)

DoC’s response to the OIA request included a note that different conservancies would certainly like to work towards a more nationally consistent way for estimating track times, which is promising news. Clearly there will always be exceptions, and it might be that actually looking at a map with some presence of intelligence could still sometimes be more reliable than an indication on any sign. Also, hopefully obviously, having a more reliable estimate based on someone else’s measurement of how long it’ll take to cover a particular distance is no substitute for taking appropriate back-up measures (like portable shelter) in case it doesn’t work out [8].

18 Comments (Open | Close)

18 Comments To "DoC Track Time Calculation Nightmares"

#1 Comment By gazza On 8 June, 2012 @ 4:38 pm

I generally find the estimated times seem to be either for the insanely fit or for the very slow…and its not always easy to tell which way its going to go when you find a sign. So I treat a sign like an project cost estimate….give or take 50%.

Of course my own fitness tends to vary greatly from trip to trip, so that probably doesn’t help.

#2 Comment By Mike McGavin On 8 June, 2012 @ 5:25 pm

True. I don’t know if it’s realistic to avoid having times stated on signs completely. That’d just confuse people who had no idea how a system worked and they’d wonder why no times were provided.

But if signs had a code in the corner like F=5 M=2 R=3 SC=200 and people could translate that to something like “5km easy flat, 2km tree-root hop, 3km wide-ish river follow, 200 vertical metre steep climb”, it might help people to better estimate a time for themselves. Or maybe it wouldn’t work at all, or people should just look at a decent map. 🙂 I haven’t exactly thought it through enough to know how practical it’d be.

#3 Comment By Robb On 8 June, 2012 @ 7:38 pm

Kia ora Mike,
Always enjoyable to read your posts. I have always been a bit bemused by the sign posted times in Aotearoa. I can write fairly expertly about one range in particular, the Ruahine.
In my time there, and study 0f it outside the park, particularly the many writings on the culling days, is that the primary premise in the Ruahine anyway, comes from just that. The times the cullers moved between huts on their respective blocks. And of course we are writing about fairly young and very fit men. I know of one old tin marker still on a tree, and inscribed upon it is “——– hut… 1 hour 30…40 minutes running” – I love that! Indeed, those rusty words are valuable to my theory. I quickly learned most of the inner signs are well off the mark. At least for me, and while not a race horse by any means, have made my way around a bit.
The other observation I will make, particularly with my new hip, is that I have yet to arrive at any hut to date where I am awarded a medal upon arriving for getting there fast. The slower I go the more I see, and funnily enough arrive in more than enough time to enjoy what may come.
Nice post Mike. Kia ora.

#4 Comment By Mike McGavin On 8 June, 2012 @ 9:23 pm

Hi Robb. Thanks for the insight. That would explain the sign in the photo at the top of this post, which announces 1 hour “down river” between Cattle Creek Hut and Mid-Pohangina Hut. It took us 2.5 hours and we weren’t going especially slowly, either.

#5 Comment By Robb On 9 June, 2012 @ 12:45 pm

Kia ora Mike – the Pohangina is a real interesting valley for the history there. Some of the hut books up near the top of the valley went back a long way and offered real insight. And I ran into an old culler in for a last look at Leon Kinvig many years ago. He told me back in the 50’s and 60’s the valley floor along the river was literally filled with shingle, making walking very easy, and that he could get from Kinvig to Pohangina base in 3 hours. The storms and cyclones of the late 60’s, early 70’s washed the layer of shingle away, leaving the large boulders and rapids to be dealt with now. And slowing down travel times considerably. By the way do you know DOC has removed the swingbridge just below Mid Pohangina? Making the only access to it by the river and some very deep pools, and if the river is even up a bit travel to or from Mid Poh will be very unlikely if not dangerous. I would write the hut itself will soon come under scrutiny.

#6 Comment By Mike McGavin On 12 June, 2012 @ 12:19 pm

Hi Robb. If that’s the case about shingle being washed away in such a way, it could explain a lot about the 1 hour sign between Cattle Creek and Mid-Pohangina… although I’d never rule out someone just having a joke with the sign. Certainly seen that on odd times before. 🙂 These days I’d not say for certain that nobody could get through that way in an hour, but I’d be amazed if they did. Then again, I guess many of the hunters in Forestry Service days travelled light-footed and often unencumbered.

I was aware if the Pohangina Swing Bridge removal, which is a real shame. There’s been a thread [16]. I could imagine some of the helicopter-using hunters wouldn’t mind the reduced access quite so much, but it seems a sad sign of the way things are going at this point in time.

#7 Comment By Paddy Janes On 13 August, 2012 @ 8:23 pm

New Zealand Handbook -Tracks and Outdoor Visitor Structures -SNZ-HB 8630:2004 defines Walking Time as”…Is expressed in hours and minutes.It is based on the estimated time it would take aperson of average fitness from the predominant visitor group to walk between two points in normal weather conditions…”
This Standards handbook applies to all localbody,district council and government agencies , indeed for any one putting in tracks for public use.
It is pretty obvious that DOC Recreation staff are not familiar with this document or some one would have responded to your article.

#8 Comment By Mike McGavin On 14 August, 2012 @ 1:32 pm

Hi Paddy. Thanks for that reference. To be honest I think there are more than a few things that DOC staff aren’t familiar with in respect to laws and regulations and such, which isn’t an intended slight at any staff so much as a disappointment that the department as a whole doesn’t seem to be very effective in making sure things are done coherently and legally. (Did that make any sense?)

I’m working on this opinion… ‘closing’ tracks and areas is another thing I’m concerned about, but that’s another story. Cheers.

#9 Comment By Mel On 24 September, 2012 @ 7:39 pm

“Predominant user group” is what makes the most difference I suspect, even if they were all using that…

#10 Comment By Mike McGavin On 22 October, 2012 @ 5:04 pm

Yep. There have been more than a few places I’ve been where it’s typical to have a variation of between about 2-6 hours. People’s pre-disposition towards what they’re expecting can have as much effect as how able they are: Someone who’s very capable and fit and wanting to quickly get to point B so they can get into a main part of their trip might skip through a section very quickly compared with another person or group there specifically to stop frequently and visit the same area.

#11 Comment By Paddy Janes On 17 August, 2012 @ 7:03 pm

Gday Mike, yes , what you say does make sense.
More so because the department employs highly trained and qualified staff, at some cost to the taxpayer.
The department also has spent many hundreds of thousands of dollars on training Huts,Tracks and Structures inspectors to ensure that facilities used by the public at large are safe. Together with a computer system which contains a complex programme called Asset Management Information System that has cost millions of dollars, one would expect a better outcome nationwide ,at least a uniformity of results based on a document put together by representatives of district councils Auckland ,Wellington ,Christchurch,FMC,Fish and Game,Frame Group and others.
Tracks,and Outdoor Visitor Structures Handbook was a direct result of Cave Creek and the need to standardise these assets .
I am certain that a thorough audit of the department would reveal many other
shortfalls in performance and finance management, but i dont know how this can be made to happen.
shortfalls in performance and financial matters, the old boys network.

#12 Comment By Mike McGavin On 17 August, 2012 @ 7:19 pm

Hi Paddy. Am I correct in thinking that’s the system which used to be the VAMS, for tracking the state and maintenance of all the stuff DOC’s meant to be looking after since post-Cave-Creek? I remember reading that it was renamed or rebuilt, but I’ve forgotten what it’s now called.

It may not be the case here, but I’ve found from my own jobs that there can be getting an art to having the right amount of documentation. Documenting things too much can cause things to get to a point where masses of time are spent documenting, then nobody reads it because it’s too hard to find or because they never knew it existed, or (in some contexts) because in practice it’s just quicker to just figure things out all over again than to locate and read someone’s step-by-step and perhaps badly-written instructions. I bet staff turnover also doesn’t help, if there’s a lot of that happening. I think you’re much better positioned than me to know what’s actually going on.


#13 Comment By Paddy Janes On 17 August, 2012 @ 9:05 pm

Gday Mike , yes ,you are correct .VAMS was replaced by AMIS.Its so complex (AMIS) areas have to have a dedicated ranger especially to monitor, amend records etc.Whereas VAMS was pretty simple.
The documentation thing and the right amount is a delicate balance ,and my working life has largely spent in equal proportion between administration and hands on physical stuff, so it sounds a bit like we are in the same boat.
To be part of an organisation , who or whatever it is, thats got bogged down in paperwork is very difficult to cope with.
Coupled with restructurings and staff changes , it is frustrating .
The department has very well written SOPs (Standard Operating Procedures)for every known task.The real problem is getting staff at Programme Manager level who are sufficiently experienced with admin matters,have practical experience in the building or related trades, have a high level of intelligence and initiative, to understand and implement these manuals and instruct junior staff accordingly .
Unfortunately i can only recall one or two that i worked for in the 20 yrs i was with the department.

#14 Comment By Mike McGavin On 24 August, 2012 @ 7:25 pm

Thanks Paddy. I think I’ve run out of comments to add to this thread, except to introspectively suggest that sometimes the most effective documentation is that which the people who apply it have a role in creating. (That way, it’s more likely that they have an active understanding of what the the rules are and why they’re consistent.) I don’t suppose this is always practical when there’s more than a small amount of staff turn-over, and without having a clearer idea of what happens inside, I also don’t want to arrogantly suggest it’s a good solution for this. Oh well.

#15 Comment By dee On 22 August, 2012 @ 5:26 pm

Late to the party here (i just found your blog) but this is something that i’ve always wondered about – when i was in Wanaka DoC had posted a sign that said it took an hour to complete part of a track – it was only 2kms and flat! Yet another sign told me it would be 4-5 hours return to go up a mountain (it took me 6hrs and i was run/walking – i felt really poorly over that one). Yet around Wellington i can usually halve the estimated time and that pretty much always ties in to what my actual time is. What i’d prefer – and would find more helpful is distances on every sign as well as times – why not have both? Some signs and maps have distances for tracks but i’ve come across alot that don’t – having both lets me guess my time accurately esp. considering the odd way each area judges time that you’ve explained.

#16 Comment By Mike McGavin On 24 August, 2012 @ 7:31 pm

Hi dee, and thanks for the comment.

Yes, the biggest potential issue I can see with noting distances is that (in my experience) terrain can also have a significant effect…. and the same change in terrain can have a totally different effect depending on the capabilities of the person, too, which just adds to the mess. (Given two people at the same speed on the flat, one might get up a steep hill twice as fast as the other.) 🙂 There are so many dimensions which all have an effect.

Well, it probably wouldn’t hurt to include distances. They’d often be marginally more useful than times, but moreso if there was context for the distance and as long as the person reading the sign knows how to interpret the info usefully according to them.

#17 Comment By Paddy Janes On 27 August, 2012 @ 1:52 pm

Hi Mike , a way to maybe avoid the confusion over “times to walk” a track would be to not show them on the signage , but just show distance for BCA tracks.
There is provision to recommend amendments to SANZ manuals and when i muster up a bit of documentary evidence supporting this i will do so.
I did hut wardening in the Tarrys for a few years in the early 1990,s, so we may have met.

#18 Comment By Mike McGavin On 8 October, 2012 @ 7:20 pm

Hi Paddy. Probably not unless you’ve been in the Tararuas recently, as I’ve really only been in the tramping world for the last few years. (Late starter, but glad to be here.)

Ultimately for me I think the most reliable thing is usually to look at an actual map and estimate based on contours and other information compared with what I know about myself and/or other people with me, although it’s not fail-safe, and not likely to be enticing for many visitors.