A system that identifies bus passengers by Wi-Fi and Bluetooth signals emanating from their phones could help to optimise bus stop locations and routes.
University of Washington (UW) researchers have developed the inexpensive system which detects the media access control (MAC) address of smartphones that is unique to each passenger’s device.
This information can then be used to identify when an individual has got on or off the bus, how many people use a given stop and even how long they wait to transfer to another bus.
The $60 (£43) device can provide real-time travel data that is more accurate than other measurement systems used which 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.
UW professor, Yinhai Wang, said the technology could be used at a large sporting event to determine the number of attendees for a given team that take the bus or other forms of public transport after a match.
This data could be then used the next time they play to ensure the correct number of buses arrive at the right time.
The research team tested the system in May 2015 by installing sensors on bus services running through the university.
Algorithms were also developed to filter out all the signals from mobile devices running Wi-Fi or Bluetooth carried by people who were near the bus, but not actually riding on it.
"That's probably the hardest part of the whole thing," said co-author of the study Kristian Henrickson, “We have to make sure we filter out those addresses."
The project is now looking at how different social groups use technology to ensure that data collected accounts for all segments of the population like the elderly, or low-income people who may not carry mobile devices or use wireless networks.
"We were able to prove the concept and demonstrate that it's much cheaper to collect data this way," Wang said. "This is really just at the beginning stage, but this technology is going to become more universal in the age of smart cities."