The nation's first predictive parking program has debuted in downtown Pittsburgh, directing drivers based on real-time data and historical models.

ParkPGH, available through an iPhone app, website, mobile site, SMS service and phone number, calculates the number of parking spaces available in 10 lots – over 5,300 spaces, and 25 percent of the garage parking in downtown Pittsburgh. Every 30 seconds, the system updates its count of available spaces and directs parkers to a garage that will be able to accommodate their car.

It sounds like any number of parking apps, but there's a twist: Unlike similar systems, like San Francisco's Streetline, ParkPGH not only counts existing open parking spaces but predicts which lots will have a free space by the time a driver gets there. The system relies on an algorithm designed by Dr. Robert Hampshire at Carnegie Mellon University, and uses historical data and current events to predict how many parking spaces will be filled at any given time. For instance, the model predicts that a Celtic Thunder concert tonight may slightly increase demand in garages around the Benedum Center.

The research was brought to reality through the Pittsburgh Cultural Trust, and developed with support from Traffic21, an intelligent transit research program within Carnegie Mellon's Heinz College. As Pittsburgh is a learning lab for future research, it wouldn't be a surprise if other cities' smart parking programs gained predictive functionality.

Though we're miles away from Pittsburgh, we gave the app a try and found it illuminating. At the beginning of a busy work day, two garages on a main street were filled with cars while another garage less than half a block away was only at 52 percent capacity. The site also listed all rates, including specials, and whether any nearby events would affect availability later in the day. Turns out that the half-empty garage we found actually cost $5 more a day than the already full garage, and would probably fill up by 9 am.

That information may be old news to frequent commuters, but it's important for families and tourists deciding whether to trek downtown to visit a museum or see a show. The information can also help garages set rates and planners determine the hours and locations of peak demand.

Photo: Flickr/Planetschwa. Two Andys – Carnegie and Warhol – look for a space in a Pittsburgh garage.