Your Smartphone Signals Could Make That Bus Arrive On Time

On a rainy Seattle morning, Cameka Knock stands at a bus stop near Edmonds and Rainier in Columbia City.

She takes the bus to school, and she says that recently the one she was trying to catch passed her by because it was full.

"I was late that day and I got in trouble," Knock says. It was embarrassing. "You know, I can't just tell them the bus was too full. So I had to just wait for another bus, a whole 10 minutes."

At the same stop, bus rider Crystal Matteson says she takes the bus every day to get where she's going. She just wishes the service was more predictable.

"I took the same bus one day and got to where I was going 10 minutes early, I took the same one the next day I got there 10 minutes late. So it’s just a little too fluctuating," Matteson says, laughing.

Engineering researchers at the University of Washington are working on ways to improve bus service in the Puget Sound area and beyond by tracking bus riders like Knock and Matteson, using their smartphones.

Where they get on and off. How long they're riding the bus. Even how many people are at a given stop.

Researchers tested the method using the UW Health Sciences' express bus system. They tracked the Media Access Control addresses of Wi-Fi and Bluetooth signals to gather the movement patterns of bus riders.

"The sensors are actually very simple," says Kris Henrickson, a graduate student who worked on the project. "We didn't develop any proprietary hardware."

He says the sensors were basically smartphones that researchers deployed on the UW buses. The researchers then developed applications to run and collect the data and communicate with UW engineering servers.

Henrickson says that the goal of gathering that data is to help transportation planners make better decisions, such as how often to deploy a bus in a given area.

For now, agencies like King County Metro do not track people's cell phones in this way. But Victor Obeso with Metro Transit says, it is great to see a project like this happening so close to home.

But he says the ability to collect this kind of information about transit rider patterns could definitely help them fine-tune their service for passengers.

“It could help with informing levels of service or how long we run service,” Obeso says. “It could show us the nature of demand, or help us make sure that we have facilities that are properly sized where there's a lot of activity occurring. It can inform pathway decisions, and where we need additional sidewalks.”

Obeso says transportation agencies are moving in the direction of collecting more and more passenger data to inform service decisions. He says for now agencies mostly use infrared passenger counters on buses and collect data from passenger ORCA cards.

It’s a long way from when they used to deploy people on the street to count bus riders.

But not everyone gets excited when they hear the words "tracked" and "smartphone."

UW professor Yinhai Wang headed up the research, and he says tracking Media Access Control addresses is a better method than most to address privacy concerns.

“It’s a pretty long string of characters, like a 48-character-long string,” says Wang. “Nobody could really remember a MAC address. So it’s not as bad as using, say, a vehicle license plate for data collection.”

Wang says address identifiers could be changed to prevent the address from being linked to a specific person. It’s also easy for anyone to opt out of the process, by simply turning the Wi-Fi or Bluetooth signal on your phone OFF.

But researchers hope people would eventually see a value in helping give transit agencies access to better information.

In the meantime, Wang says, collecting and using this kind of data not only takes us on the path toward smart transportation, but into the realm of smart cities. In that city of the future, a lot of sensors would collect big data that could be used to improve all kinds of public services.

Photo: “Bus stop” by Dan Ox on Flickr (CC BY-SA 2.0)