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So I have a list of GeoPositions and I need to find the distance covered in that order? I know I can find the distance from each city and then add them all up but I was wondering if there is any easier way to do it?

GeoGraphics[{Red, GeoPath[{GeoPosition[{18.96`, 72.82`}], 
GeoPosition[{18.98`, 73.27`}], GeoPosition[{17.92`, 73.67`}], 
GeoPosition[{15.42`, 73.78`}], GeoPosition[{15.33`, 76.46`}], 
GeoPosition[{13.21`, 75.99`}], GeoPosition[{12.3`, 76.6`}], 
GeoPosition[{11.411746`, 76.69466`}], 
GeoPosition[{11.58`, 75.59`}], GeoPosition[{12.88`, 74.84`}], 
GeoPosition[{12.97`, 77.56`}], GeoPosition[{13.63`, 79.41`}], 
GeoPosition[{13.09`, 80.27`}], GeoPosition[{12.62`, 80.1994`}], 
GeoPosition[{9.92`, 78.12`}], GeoPosition[{10.23`, 77.48`}], 
GeoPosition[{10.08`, 77.0597`}], GeoPosition[{9.61`, 77.15`}], 
GeoPosition[{8.51`, 76.95`}], GeoPosition[{8.078`, 77.541`}], 
GeoPosition[{17.400000000000002`, 78.48`}], 
GeoPosition[{19.89`, 75.32000000000001`}], 
GeoPosition[{24.580000000000002`, 73.69`}], 
GeoPosition[{24.6`, 72.7`}], GeoPosition[{26.92`, 70.9`}], 
GeoPosition[{26.92`, 75.8`}], GeoPosition[{27.1`, 77.67`}], 
GeoPosition[{27.19`, 78.01`}], GeoPosition[{28.6`, 77.22`}], 
GeoPosition[{29.98`, 78.16`}], GeoPosition[{30.34`, 78.05`}], 
GeoPosition[{30.73`, 79.07000000000001`}], 
GeoPosition[{29.400000000000002`, 79.12`}], 
GeoPosition[{29.38`, 79.45`}], GeoPosition[{31.1033`, 77.1722`}], 
GeoPosition[{32.27`, 77.17`}], GeoPosition[{34.17`, 77.58`}], 
GeoPosition[{32.71`, 74.85000000000001`}], 
GeoPosition[{31.64`, 74.87`}], GeoPosition[{26.85`, 80.92`}], 
GeoPosition[{24.85`, 79.93`}], GeoPosition[{23.17`, 79.94`}], 
GeoPosition[{25.32`, 83.01`}], GeoPosition[{24.71`, 84.98`}], 
GeoPosition[{22.57`, 88.36`}], GeoPosition[{25.57`, 91.87`}], 
GeoPosition[{26.35`, 92.67`}], GeoPosition[{27.34`, 88.61`}], 
GeoPosition[{27.05`, 88.26`}], GeoPosition[{17.73`, 83.3`}]}, "Rhumb"]}]

That is the code for how I graphed it.

Also, I used the FindShortestTour function to find the shortest route and I found it. Now I want to find the total distance covered using that route.

    locs = {GeoPosition[{18.96`, 72.82`}], GeoPosition[{12.97`, 77.56`}], GeoPosition[{27.19`, 78.01`}], 
  GeoPosition[{19.89`, 75.32000000000001`}], 
  GeoPosition[{24.85`, 79.93`}], 
  GeoPosition[{32.71`, 74.85000000000001`}], 
  GeoPosition[{15.42`, 73.78`}], GeoPosition[{26.92`, 75.8`}], 
  GeoPosition[{24.580000000000002`, 73.69`}], 
  GeoPosition[{26.92`, 70.9`}], GeoPosition[{34.17`, 77.58`}], 
  GeoPosition[{32.27`, 77.17`}], GeoPosition[{31.1033`, 77.1722`}], 
  GeoPosition[{27.34`, 88.61`}], GeoPosition[{27.05`, 88.26`}], 
  GeoPosition[{8.078`, 77.541`}], GeoPosition[{29.98`, 78.16`}], 
  GeoPosition[{29.38`, 79.45`}], GeoPosition[{28.6`, 77.22`}], 
  GeoPosition[{30.34`, 78.05`}], GeoPosition[{31.64`, 74.87`}], 
  GeoPosition[{27.1`, 77.67`}], 
  GeoPosition[{17.400000000000002`, 78.48`}], 
  GeoPosition[{12.88`, 74.84`}], GeoPosition[{25.57`, 91.87`}], 
  GeoPosition[{17.73`, 83.3`}], 
  GeoPosition[{30.73`, 79.07000000000001`}], 
  GeoPosition[{13.63`, 79.41`}], GeoPosition[{10.23`, 77.48`}], 
  GeoPosition[{22.57`, 88.36`}], GeoPosition[{18.98`, 73.27`}], 
  GeoPosition[{25.32`, 83.01`}], GeoPosition[{17.92`, 73.67`}], 
  GeoPosition[{24.71`, 84.98`}], GeoPosition[{26.85`, 80.92`}], 
  GeoPosition[{9.92`, 78.12`}], GeoPosition[{23.17`, 79.94`}], 
  GeoPosition[{24.6`, 72.7`}], 
  GeoPosition[{29.400000000000002`, 79.12`}], 
  GeoPosition[{11.411746`, 76.69466`}], GeoPosition[{8.51`, 76.95`}], 
  GeoPosition[{13.09`, 80.27`}], GeoPosition[{12.3, 76.6}], 
  GeoPosition[{13.21, 75.99}], GeoPosition[{9.61, 77.15}], 
  GeoPosition[{10.08, 77.0597}], GeoPosition[{15.33, 76.46}], 
  GeoPosition[{12.62, 80.1994}], GeoPosition[{26.35, 92.67}], 
  GeoPosition[{11.58, 75.59}]}



(* locs are used in FindShortestTour function *)
tour = FindShortestTour[locs][[2]]

{1, 33, 7, 24, 50, 40, 29, 46, 45, 41, 16, 36, 48, 42, 28, 2, 43, 44, \
47, 23, 26, 30, 25, 49, 14, 15, 34, 32, 37, 5, 35, 18, 39, 27, 12, \
11, 6, 21, 13, 20, 17, 19, 3, 22, 8, 10, 38, 9, 4, 31, 1}

And then I graphed it:

GeoGraphics[GeoPath[locs[[tour]]], GeoRange -> Automatic]

Pretty much, I want to compare the two distances and see which one is the better route.

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I don't know any direct way to do what you wantand I agree that it would be an improvement if in a future release GeoDistance will supports a GeoPath as argument.

But even now it's not so difficult to compute the distance along a path with with a not-so-"brute" way and this definition:

geoPathDistance[locations:{__GeoPosition}] := 
  Total[GeoDistance @@@ Partition[locations, 2, 1]]

For example for the original localtions list

geoPathDistance @ locs

Quantity[49069.6, "Kilometers"]

Or for the shortest tour (as @MichaelE2 shown it's enoug to permute the list of locations according to the permutation returned by FindShortestTour):

geoPathDistance @ locs[[tour]]

Quantity[11102.5, "Kilometers"]

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  • $\begingroup$ How do I find it for the path that was found using FindShortestTour ? @unlikely $\endgroup$ – Sarah Apr 29 '15 at 21:21
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Another way:

Module[{dist = 0},
 Fold[
  (dist += GeoDistance[##]; #2) &,
  locs[[tour]]];
 dist]
(*  Quantity[6898.75, "Miles"]  *)

If locs is the other path to compare with:

Module[{dist = 0},
 Fold[
  (dist += GeoDistance[##]; #2) &,
  locs];
 dist]
(*  Quantity[30490.5, "Miles"]  *)
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