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Google Maps: How to create custom directions
How to do it on your desktop
Most take the wrong path of trying to create their route under "My Maps". Instead, it's smack-on-the-forehead simple...
1. You create a starting destination, and then add others along the way where you would stop for gas/food and a final destination. These appear as the points with letters on your map.
If you don't like the route that is proposed between
your destinations, you drag that purple route to where you want it to be. A
small white dot appears that you can move or delete later if needed
(use right-mouse clicking to get the options).
Note: If your intention is to send your custom route to a smartphone (see section below), just dragging the route instead of creating intermediate destinations, will be insufficient.
3. When you are happy with your route planning and want to share, use “Share or embed map > Share Link" and then copy the URL to be shared.
Here are related tutorials that can further help:
How to do it on your smartphone
Since the middle of 2016, you can plan routes with multi-waypoints on the phone's GM (need version 9.31) for directions.
Start by entering a destination, then add multiple "stops", which can be re-ordered easily.
The "Add stop" feature has been available since mid-2016 with version 9.31.
How to transfer a GM route made on your desktop to your Garmin Zumo 590/595
Create route in GM on your desktop, save a KML file.
Use BaseCamp on your desktop.
Import KML file as a track. Convert it to a route.
Save file for Zumo unit, by using "Send To".
Use Zumo to import the route. Connect USB cable to desktop. Turn it on.
Import the route. Use "Trip Planner" app.
Move Zumo to the bike. Turn it on. Use "Trip Planner" app.
Demonstration in this video: YouTube > How to plot a route on Google Maps and Navigate it on a Garmin Device.
How to transfer a GM route made on your desktop to your Android phone
a) Capture the URL and email it to yourself and view the link from the phone (open it with GM). Video demo: YouTube > How to Add Multiple Destinations on Google Maps for Android?
b) Capture the URL, put it on a web page. Open that link from the phone and choose GM to view.
c) From the desktop, just do "Send directions to your phone" (must have a phone under the same Google account)
Now you know. Happy route planning.