The problem here is that each time you stop for a traffic light or for a break, rather than pause, your ride will stop. This will cause a new ride to start when you start moving again. Both GPS units and phone apps have an auto pause feature that work that way but they don't stop the ride id you're not moving. It's why you have to manually start and stop a ride with the current systems out on the market.

GPS, on the other hand, is constantly receiving and sending data to the comm port. On a phone, it does it the entire time you have the phone turned on even if you don't have any apps accessing it. The same thing goes for a GPS computer. Once you turn on the power, the GPS connects to the satellites and sends the data to the com port. So if you don't have any sensors connected to your GPS computer or phone app, the ride will never end until you power off the device.