How to get directions from Google Maps into Gaia Maps for iOS so you can use them offline

I wanted a way to download directions from Google Maps onto an offline mapping program on the iPad so that I could use the iPad for navigation even when I don't have my cellular service.  I have an iPad with 3G, but because I am a tightwad I only turn the 3G service on when I am on long trips. Also, we go plenty of places with little or no cell service out here in the west, so even if I wasn't a cheapskate I would want this capability.

It turns out that it is not that hard transfer directions from Google Maps into Gaia GPS as a route (not turn-by-turn directions, sorry) that you can view as a colored line on the map.  These days my favorite iOS offline maps app is Gaia GPS.  It can do offline street maps (Mapquest using Open Street Maps), satellite view, and topo maps.

• Sign in to Google on your computer browser, since you will need to work with the "My Maps" feature in Google Maps.
• Go to Google Maps and get directions to the place you want to go.
• At the bottom of the list of directions click the "Save to My Maps" link
• Select "Save to a new map" from the drop down that asks which map you want to save to.
• You will be taken to your new map in My Maps.
• Find a link called KML on the left sidebar, just under the title of your map, and click it.
• This will open a save file dialog for a KML file. Save it to your desktop.
• Now transfer the KML file from your computer to your iPad.
• One way to transfer the KML file to Gaia GPS is via email.
• Email the KML file to yourself.
• Open the Email on your iPad and open the attachment using Gaia GPS.
• Another way to transfer the file is via iTunes
• Plug your iPad into your computer
• Go to the tab for your iPad in iTunes and click the Apps button to get to a list of your apps
• Find Gaia GPS in the list of File Sharing apps
• Click the Add button at the bottom of the file list for Gaia GPS. This will open a dialog where you can select your KML file.
• After you have selected your KML file in iTunes, open Gaia GPS on your iPad. It should pop up a dialog saying there is a KML file waiting to be imported and asking you if you want to import it now. Do so.
• Once you have imported the KML into Gaia GPS it won't automatically show up on the map.  You have to first tell Gaia GPS to display the route on the map.
• Go the the Saved screen in Gaia GPS
• On the Saved screen click the button on the top left for saved routes (it looks like two amoebas with stringy appendages)
• Your KML file should be listed at the top of the list of routes with an on/off switch next to it. Turn it on.
• Go back to the Map screen in Gaia GPS and your route will show up as a colored line. 

How to get a route from Google Maps on to an iPad so you can follow it offline

I wanted to find a way to download a route from Google Maps onto my iPad 3G so that I could follow the route on a map offline.  I know that with the iPad 3G data plan turned on you can just use the Maps app to find and follow directions, but I am a frugalista and I like to keep the 3G data plan on my iPad turned off except when I am on long trips.

Here is the procedure I worked out, which requires that you own the $3.99 (as of Dec 2011) MotionX GPS HD app.

• Go to Google Maps and look up directions to the place you want to go.
• At the bottom of the directions click the Save to My Maps link.
• Go to Google My Places (fka My Maps) and select the map with directions you just saved.
• Click the KML link to download a KML file of the directions to your computer.
• Go to http://www.gpsvisualizer.com/ select the KML file to upload and pick GPS format for the output and click Go.
• Email the resulting GPX file to yourself.
• In Mail on your iPad open the email, tap the attachment, and select open in MotionX GPS HD app.
• This will open the MotionX GPS HD app where you can complete the import of the GPX track.
• This will just import the track into the MotionX GPS HD app.  You need to separately download OpenStreetMaps for the relevant area in MotionX GPS HD in order to have the maps available offline.

This doesn't give you turn by turn directions, but it does give you a simple line on a map that you can follow while offline.

Notes on using Google Maps to show hiking trails

I have been working on using Google Maps to show the routes of various hiking trails in my area. It can be done, but it's not very straightforward. Here are cursory notes on what I learned in the process (i.e. this is not a detailed how-to).

Initially I used Google "My Maps." Here are the characteristics of Google "My Maps" relevant to mapping hiking tails:

• Google "My Maps" displays the length of a path when you click on it, which is good for showing people how long a trail is.
• You can upload a GPX track to it by the roundabout method of importing the GPX track into Google Earth and then exporting it from Google Earth as a KML file, which you can then import into Google My Maps. Or you can use the GPS Visualizer web site to convert GPX files to KML files: http://www.gpsvisualizer.com/
• Unfortunately Google My Maps has a limit on the number of placemarks and lines it will display at one time. If you add exceed this number of items Google My Maps will automatically bump some of your items to a second page so that it is impossible to see everything at once.
• Another unfortunate characteristics of Google My Maps is that it apparently has a limit on the number of points that can be in a single line. If you exceed this limit Google My Maps will split the track into two lines of the same color. I searched for a long time and couldn't find any work around. See: http://www.google.com/support/forum/p/maps/thread?tid=7d6964088b224b32&hl=en

There is a workaround to avoid having your placemarks/lines broken up into multiple pages if you have a lot of them. This workaround also gets around long tracks being broken up into multiple lines. You can display a KML file using Google Maps by entering the http address of the KML file in the search box of Google Maps. When a KML file is displayed this way there is apparently no limit on the number of items that can be displayed (or at least the limit is higher). Also, when you display a KML on Google Maps using this method your long tracks/lines will not be broken up into separate lines.

If you don't want to upload a KML file to a web server to display it you can also display all the items of a Google "My Maps" map that has too many items to fit on one page using this trick. Just right click on the View in Google Earth link in My Maps to get the http address of the KML file, and then enter that in the search field in regular Google Maps. I have seen forum postings that some people have had problems with this, so posting a KML file to a web server may be the most reliable approach.

I decided to go with uploading my KML file to a web server and then searching for its URL in Google Maps. Once I that I faced the choice of whether to continue to use Google My Maps to edit my KML and then export the KML file, or to use Google Earth to edit the KML. Although both Google Earth and Google My Maps are awkward to work with if you have a lot items, I decided to go with Google Earth.

The problem with using Google Maps to render a KML file is that you don't get distance measurements on the length of lines. I decided to work around that by uploading my KML to Google My Maps and then clicking on tracks/lines there to find out the distance. There is also this hand web site that will tell you the length of a Google Earth track/line: http://www.emaltd.net/google/gec/utilities/index.asp?l=en

How to download KML data from Google My Maps

I had put a lot of time into a particular custom map under Google "My Maps" and I wanted to make an offline backup of the data. I clicked on the "View in Google Earth" button when viewing my Google "My Maps" map and it downloaded a KML file which I could open in Google Earth. However, when I opened the KML file in a text editor I saw that it didn't contain any actual map data but instead just had a http URL pointing back to Google Maps. After some experimentation I discovered that I could download the actual map data by taking the URL from inside the downloaded KML file and changing each instance of "&" into plain old & and then pasting the edited URL into my browser address bar. This returned a real KML file with real data.

Incidentally, you can display a KML file on Google Maps by uploading the KML file to any webserver and then putting the http address of the file in the Google Maps search box and hitting enter. Google maps will then display the KML file placemarkers and paths on Google Maps.