On any given bus ride, passengers read, text or while away the hours in any way their mobile phones let them.

But experts say in the future, more could be done, with mobile devices adding 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 could help transit agencies collect valuable real-time data to provide better service.

To improve efficiency and ensure that buses are meeting the greatest needs in a community, transit agencies today typically rely on passenger surveys, head counts and smart card swipes that may only offer partial information about how people are using the transit network.

But the transportation engineers from the US say their sensor system - which costs about $60 per bus - can detect a particular mobile device as it boards and leaves the bus, offering complete and real-time travel data.

The system collects MAC addresses from devices at the time and location they are detected, and each address is anonymised for privacy.

Tests so far have allowed origin and destination data from the remote sensing system to tell researchers how many people got on and off at various stops.

Transit agencies are always seeking that type of information to inform decisions about changing routes or service levels, or to determine how frequently buses should run, whether they need larger buses at certain times of day, and how to meet demand and operate the transit system most effectively.

Their studies have only just started, and are now looking at innovative ways to use data to improve transport services on both personal and structural levels.