Map Measurements: Meandering Trails

[Carl in FL]

Does anyone have any tricks and/or tips for measuring the ground distance
of a meandering trail on a map? There are "map wheels" one can buy, very
similar to the distance measuring wheels used in the real world (a bit
smaller though!) yet these seem to be fairly clumsy to use on a tight,
twisty trail.

I am thinking if I tape the map to the wall and then insert little map pins at
every turn in the trail, then I can string a string along the pins and
measure the string. Before I actually do this and put a zillion little holes in
my maps, I though I'd ask if there was something simpler.

I do not care about the errors induced by the curvature of the Earth, or
elevation gain and loss, but I do want something better than measuring
the straight-line distance and then saying it's longer than that. A target of
+/- 10% would be a good place to start.



Thanks!
Carl in FL

[Hooch]

Use a piece o string. Lay the string down on the map along the route you wish to follow. Measure from point a to point b. Then, after you czech yourp map's scale, you know your distance. Example: If your scale is 2.5 miles/inch and you have 5 inches from a to b, then the distance is 12.5 miles.

[atraildreamer]

Use a piece o string. Lay the string down on the map along the route you wish to follow. Measure from point a to point b. Then, after you czech yourp map's scale, you know your distance. Example: If your scale is 2.5 miles/inch and you have 5 inches from a to b, then the distance is 12.5 miles.

A piece of electrical solder or soft wire will work too. Be aware that a lot of these maps, especially topos, are not really that up to date. Some of them have features that were mapped 40-50 years ago, especially where new roads and housing tracts, shopping centers, etc. have been built. Even in the protected park and wilderness areas changes occur. The trail that was marked on the topo map may have been rerouted numerous times over the years. Ask 10 hikers if they know the length of the AT and you will probably get 10 different answers...and they all may be correct. The best measurements are done by the people on the trail(s) pushing the bicycle wheel measuring gizmo. Get a good guide book that lists the most recent trail changes and measurements for the most accurate distances...but there may have been more changes to the trail(s) before the guide book went to print!

[Carl in FL]

A piece of electrical solder or soft wire will work too.

Hey, that's really a good idea. It will sorta hold the shape while I work the
map trail and then massage it back into a line, as long as I'm fairly dainty
with it.

I try to double check the topos against a few other maps, and yes, there
are frequently discrepancies. I guess when the data is really shaky I'll ask
here and see what the consensus is, if there is one.

Thanks!

[Mags]

Use a piece o string. Lay the string down on the map along the route you wish to follow. Measure from point a to point b. Then, after you czech yourp map's scale, you know your distance. Example: If your scale is 2.5 miles/inch and you have 5 inches from a to b, then the distance is 12.5 miles.

That's what I do. I also add a 10% 'fudge factor' to take in natural error from using this method, relos over the years, etc.

Seems to work well.

[WingedMonkey]

That's what I do. I also add a 10% 'fudge factor' to take in natural error from using this method, relos over the years, etc.

Seems to work well.

Waxed dental floss, It's in my repair kit anyway and somewhat stiff / bendable.

[Mags]

Waxed dental floss, It's in my repair kit anyway and somewhat stiff / bendable.

Similar reason why I use the lanyard from the compass.

All good, quick and dirty ideas.

[Carl in FL]

Waxed floss. Gives me an idea. Ideally it would be something that sticks to the paper with a little bit of pressure, to hold the shape, then peels right up into a measurable line. Like really skinny pinstripe tape!

Sticky string. Anyone got a patent on that yet??

[WingedMonkey]

Something else to try is to go ahead and cut a piece of string/thread/floss for the scale on that map, say 10 miles worth. Then place one mile marks on it with either knots or ink.
You can do a quick distance check without holding your fingers on the string/thread/floss and going back and forth from the route on the map to the scale lines.
Good for laying around at night planning the next day.

[AegisIII]

Frankly, the first thing I would do is see if there is a GPS trace of the trail online, or if any aerial photos can be found at the usual places show the trail from above, and measure it using one of those ways.

Depending on the map (I'm thinking of USGS 7.5 minute topos), the measured distance (map) may be significantly off. So I would use map distance as a last resort.