A posting about GR (Grand Rondonees) by Richnan4
http://micronavigation.com/forum/index.php?topic=461.msg3142;topicseen#msg3142 brings to my mind a common navigational mistake I have witnessed working, independently, with two MRT’s, firstly in Canada and more recently in France.
Unlikely as it may seem, France has more public footpaths than Britain! In fact more than eight times the kilometres of public foot paths than in England.
The most spectacular of these are called the Sentiers de Grand Rondonees (GR) and they are all numbered GR1, GR2 and so forth. Some are incredibly long, such as the GR5 which runs from the Luxembourg border, through the Vosges, Jura and Alp mountain ranges to the Mediterranean.
The organisation that established and maintains the trail system is called the Féderation Française de la Randonnée Pédestre (FFRP) and although headquartered in Paris they have around 2000 local clubs who maintain the route markings and signs along these tracks.
The tracks are marked with white over red blazes and these signs are invariably, yet not always, prominent and frequent. Turns are always marked and there are even signs informing you if you have made a wrong turning.
I was assisting a Pelotons de Gendarmerie de Haute Montagne (PGHM), professional mountain rescue teams made up of police and some military personnel, in the Alps, to integrate satnav (GNSS/GPS) and digital mapping (GIS) into their standard operating procedures.
A key component in building the system is creating a bespoke base map for the team area.
Team members record information commonly missing from conventional mapping, such as new areas of scree, stream caused by flash floods, permanent pools of water, potholes etc.
In addition to this, the search managers compile the records of past incidents, the exact location of each one, where precise positions are marked on the map of all their previous callouts: the Incident Record Overlay (IRO).
From the IRO accident hot spots can be identified from this, safe routes determined both for walking in and for stretcher carry outs, possible kit stashes that are positioned for ease of access, and so forth.
Compiling this information with the team, an accident hotspot, already well known to them, revealed some interesting information.
It was coming out of a valley, where hikers frequently got lost. By plotting the tracks the casualties had reported that they had taken into the valley before becoming lost it became apparent that there was one track in particular, part of GR5, a wide and made up track, was the most often taken by the people who subsequently got into difficulties.
Many of the hikers were competent navigators and they maintained that they had been on the GR5 all the time and could not understand how they had subsequently become lost.
The weather conditions varied from summer to winter but in both there were regularly poor visibility conditions: in summer usually fog created by the formation of Stratus clouds in the valley towards the end of the day; this is also when the available daylight is starting to fail.
Stratus clouds are flat, hazy, featureless clouds of low altitude varying in colour from dark gray to nearly white and may produce a light drizzle or snow. They frequently form in mountain valleys and during the day rise with the warmth of the sunshine and late in the day settle back down in the valleys.
In winter the forest floor has a permanent covering of snow and in either heavy snowfall, or high winds creating spindrift and blowing the powder snow from the trees, whiteouts were a frequent occurrence and common event to many of the people who had become lost.
Studying the map it became apparent that wrong turns had been taken along GR5 repeatedly at one junction where many people incorrectly forked left.
We flew out to visit the area and surprisingly this junction had a very well marked sign. There was a remote weather monitor and to the immediate right of the track was a steel stanchion on top of which was an anemometer (wind speed measurer), in faded yet very clear acrylic paint was the unmistakable sign that this was the correct fork to follow.
It was an almost identical pattern of events that I had encountered with the Canadian MRT a few years earlier and I instantly recognised it as the phenomenon I have named Motorway Exit Syndrome - we are all susceptible to it.
In poor visibility, or at night when using a head torch, if following the edge of a track it is easy to veer off onto the wrong track if it forks, especially where the angle of the deviation is relatively low.
To avoid this error I recommend four simple actions:
1. Walk in the centre of the track.
2. When the track turns sharply walk to the other side of it to confirm that it is not an exit.
3. At frequent intervals, say every 100m pace count, stop and check the bearing you are on compared to the bearing of the track on your map where you should be.
4. If you are in a group, use out-riggers.