As long as the phone app is running in the background, an auto initiate feature is a simple thing to program into the app. It has to monitor the GPS and/or Bluetooth radio signals passing through the assigned communication ports and then start the ride. However, there are reasons why this isn't done. For starters, if you forget to stop the previous ride, your next ride becomes a continuation of the that ride. If your cycling app stores your rides on the phone, as Cyclemeter does, there is the issue of the on-board database connection. The DB connection stays open until the End or Stop button is pressed. If you don't stop the ride, the connection remains open and if you accidentally force stop the app or power off the phone, it can easily corrupt the entire database under certain conditions.

However, phone apps do display speed, HR and cadence even if the ride is not started. Distance, ride time and other metrics that require a starting point will not be tracked.