On any given bus ride, a good share of passengers are reading, texting or rocking out to music on their phones or tablets. In the future, though, those mobile devices may add more value to our transit commutes than simply filling time.  University of Washington researchers have developed an inexpensive system that uses Wi-Fi and Bluetooth signals from passengers’ mobile phones and devices to collect better data about where bus riders get on and off, how many people use a given stop and even how long they wait to transfer to another bus. The system — described in a paper that was presented at the 2016 Transportation Research Board annual meeting in Washington, D.C. on Jan. 11 — could help transit agencies collect valuable real-time data to provide better service.