Collecting Commute Data with an iPhone

We are working on an iPhone application specifically for use with ChargeCar. However, for iPhone 3G or 3GS users wanting to participate in ChargeCar now, we request that you record your commute data on your iPhone using the MotionX-GPS app. The MotionX-GPS app is available in both a full version and a free "lite" version. Both versions work equally well, but the full version enables you to have more than one track saved at a time.

Although there exist other iPhone apps which can produce GPX files, unfortunately none that we have found (including MotionX-GPS) contain the GPX timestamp precision we require. However, MotionX-GPS is unique in that it also produces a KMZ file which contains the necessary timestamp information and which can be used to create a GPX which will work with

See below for instructions on how to record your commute with MotionX-GPS on your iPhone 3G or 3GS, export it, and then convert it to a form usable by

I. Before you go:
  • To record your commute, first turn on your iPhone, start the MotionX-GPS app, and make sure your iPhone has a clear view of the sky. It may take a minute or so for the iPhone's GPS receiver to get a good signal from the satellites, so it's best to allow yourself a little extra time before you start driving.
  • Tap the red arrows in the bottom-right corner of the screen until you see the latitute/longitude page (Figure 1). You'll see a red globe in the top-right corner while the GPS acquires the satellites.
  • After a minute or so, you should see the globe turn blue and green and the GPS Signal field will have several green bars. Keep waiting until the the Accuracy field is less than 100 ft or so (Figure 2).
Figure 1: Waiting for a GPS signal Figure 2: Ready to go!
II. Recording and saving your commute:
  • Once you have a good signal and accurate position, tap the red right arrow once to go to the Track Recorder screen (Figure 3).
  • Tap the large, green Start Track button to begin recording your commute. You'll hear a spoken 3-2-1-Go! countdown and then the recording will begin. Place the iPhone on your dashboard or somewhere safe where it has a clear view of the sky, and begin your drive.
  • When you have reached your destination and have come to a complete stop, click the amber Pause Track button to stop recording. All three buttons will then be enabled (Figure 4), so click the blue Save Track button to save your track.
Figure 3: Track Recorder screen Figure 4: Ready to save your drive
III. Exporting your commute data:
  • Once the track is saved, tap the red left arrow button three times to go to the Logbook page (Figure 5). The Logbook page has two tabs, Waypoints and Tracks, so tap the Tracks tab if necessary.
  • Now tap your saved track to view the Track Summary page (Figure 6).
  • Tap the blue Share Track Now button at the bottom of the screen to go to the sharing page (Figure 7).
  • The top of the sharing page provides a space where you can optionally enter some notes about your drive. If you think it might be a while before you get a chance to upload the data to, this is a good place to write some reminder notes such as a brief summary (e.g. "Home to Work"), the temperature, weather conditions, etc.
  • Now scroll down the sharing page until you see the Email Sharing section. Turn it on, then enter your display name and email address (Figure 8).
  • Click the green Share button in the bottom-right corner of the screen to email the GPX file to yourself. The email will contain two attachmens, a GPX file and also a KMZ file. Although the GPX file does not contain the necessary timestamp precision, the KMZ file does and the next steps will explain how you can convert it to a GPX for use with


IV. Converting the KMZ to a GPX:
  • Once you have exported the KMZ, you are now ready to convert it to a GPX file which can be uploaded to To perform the conversion, you will need to first download our MotionX-GPS KMZ conversion tool. The conversion tool is a Java application packaged in a double-clickable jar file. You'll need to have Java 1.5 or later installed, but otherwise you should be able to just download it and double-click it to run the application (Figure 9).
  • Click the "Choose..." button to find and select the KMZ file you want to convert. Once it's selected, the "Convert" button should become enabled.
  • Click the "Convert" button to generate a GPX file from the information contained within the KMZ file. When it's complete, you'll see a confirmation message which will also display the full path to the new file. You may now upload this new GPX file to Thank you for your participation!
Figure 5: Tracks screen Figure 6: Track details
Figure 7: Sharing screen Figure 8: Sharing via email
Figure 9: MotionX-GPX KMZ-to-GPZ Converter


ChargeCar All Rights Reserved Press Contact Us