Solving TSPs with the Google Directions API
Google also provides a way to solve simple TSPs of real-world locations without downloading OR-Tools. If you have a Google Directions API key, you can solve TSPs of real-world locations with the Directions API , providing the locations in a URL and getting the response back as JSON. You'll need your own free Directions API key for development, or an enterprise key for commercial use.
As an example, here's a URL that can be used to find a short tour of winemaking regions in South Australia, beginning in Adelaide. If you want to try this from your browser, replace API_KEY at the end of the URL with your key.
https://maps.googleapis.com/maps/api/directions/json?origin=Adelaide,SA&destination=Adelaide,SA&waypoints=optimize:true|Barossa+Valley,SA|Clare,SA|Connawarra,SA|McLaren+Vale,SA&key=API_KEY
The result will be a long JSON response detailing the solution, complete with Google Maps directions:
{
"routes" : [
{
"bounds" : {
"northeast" : {
"lat" : -33.8347115,
"lng" : 140.8547058
},
"southwest" : {
"lat" : -37.3511758,
"lng" : 138.4951576
}
},
"copyrights" : "Map data ©2014 Google",
"legs" : [
{
"distance" : {
"text" : "139 km",
"value" : 139119
},
"duration" : {
"text" : "1 hour 51 mins",
"value" : 6648
},
"end_address" : "Clare SA 5453, Australia",
"end_location" : {
"lat" : -33.8333395,
"lng" : 138.6117283
},
"start_address" : "Adelaide SA, Australia",
"start_location" : {
"lat" : -34.9285894,
"lng" : 138.5999429
},
"steps" : [
{
"distance" : {
"text" : "70 m",
"value" : 70
},
"duration" : {
"text" : "1 min",
"value" : 6
},
"end_location" : {
"lat" : -34.9285338,
"lng" : 138.6007031
},
"html_instructions" : "Head \u003cb\u003eeast\u003c/b\u003e on \u003cb\u003eReconciliation Plaza\u003c/b\u003e toward \u003cb\u003eVictoria Square\u003c/b\u003e",
...