Aaron Steinfeld's iPhone told him the next Port Authority bus would arrive at the Oakland stop at Forbes and South Neville avenues in two minutes and that it would be a 69 Trafford.
A few minutes later, it also accurately forecast the arrivals of a 61D Murray and a 61A Wilkinsburg.
Welcome to the big time of real-time, Pittsburgh transit riders.
Researchers at Carnegie Mellon University on Wednesday unveiled an iPhone application that tells transit riders when the next bus or rail car will arrive at their stop and whether seats are available.
Called Tiramisu, Italian for "pick me up," the system uses information obtained from riders who are already on board to predict when a vehicle will arrive at subsequent stops.
Pittsburgh now joins scores of other cities where transit riders have access to real-time information, not just printed schedules that often can be unreliable.
Tiramisu counts on riders to activate the application, record how full the bus is and press a button allowing the phone to share a GPS trace with the system's server. It then relays the information to other riders.
In tech-speak, it's called "crowdsourcing" -- letting a large group of people generate information that is helpful to others.
"You just need one person on a bus to give everyone on the route the information," said Mr. Steinfeld, senior assistant scientist in CMU's Robotics Institute. "This is a very Pittsburgh way of doing things -- the community helping the community."
It would have cost tens of millions of dollars for the Port Authority to develop its own real-time tracking system, something the agency could not afford, he said.
"This is a great alternative that CMU came up with," authority spokeswoman Heather Pharo said. "Anything that has the potential to improve a rider's knowledge and experience of the system also has the potential to boost ridership."
CMU researchers cited another possible benefit: If riders know they have some time before the bus arrives, they might patronize nearby businesses.
If no one is using the Tiramisu application on a particular bus, the system will use accumulated historical data to predict arrival times. And if that is not available, it will deliver arrival times based on the Port Authority schedules, Mr. Steinfeld said.
Obviously, the more people who use Tiramisu, the better it will be. "We're kind of hoping a lot of people pick this up and begin using it, to get the ball rolling," he said.
Riders seemed eager to try it.
"That's great," said Irene Arduini of Point Breeze, who rides daily to work at the University of Pittsburgh. She said she has used real-time information on her iPhone to navigate New York City's transit system.
Abraham Gonzalez, a student at Pittsburgh Allderdice High School, said he planned to download the app as soon as the Android version is available, which will be soon, according to the CMU researchers.
Another Tiramisu feature is the ability of riders to instantly report any problems or make suggestions to Port Authority. If a seat is broken, for example, the rider can take a photo, add text and notify the authority, and the message will automatically convey the time, bus and location from which it was sent.
The application also can be used to find the nearest bus or rail stop.
It was developed by researchers in the Rehabilitation Engineering Research Center on Accessible Public Transportation, a collaboration of CMU and the University of Buffalo-State University of New York that focuses on the transportation needs of disabled people.
The application has special benefits for riders with disabilities, Mr. Steinfeld said. For instance, it lets those who use wheelchairs know if there is room on the next bus.
Also on the development team are Anthony Tomasic, senior systems scientist in the Institute for Software Research, and John Zimmerman, associate professor in the Human-Computer Interaction Institute.
The application can be downloaded for free from the iTunes app store or by visiting www.tiramisutransit.com.