Sensors alert drivers to parking spaces

Stressed-out Boston drivers may soon be getting some much-needed relief — a smartphone app that helps them find the most precious commodity in the city: an empty parking space.

The Herald has learned that the city is testing out a smart parking app that uses sensors to guide motorists to metered spaces that are likely to be unoccupied.

The pilot program, run by the company Streetline, now is being used on only a few dozen spaces in the Government Center area but could be expanded in the future to other areas of the city. The Menino administration still has not made an official decision to go ahead with the program, sources said.

But the Herald found a number of sensors, which look like oversized hockey pucks, embedded in the pavement on New Chardon Street, Cambridge Street and a few other downtown streets.

All drivers have to do is download a free app called “Parker” on their iPhone or Android, and the app, using guidance-based technology like GPS, will let the driver know where and how many spaces might be available. A green circle means a space is empty, blue means iffy, and red means the space is probably taken.

The Herald tested out the Parker app last week and found four green spaces that were supposed to be free on New Chardon Street. And when we arrived on the street, the spaces were indeed empty.

The sensors right now are on metered spaces but in the future could be placed in private or city garages so drivers looking to attend a game at Fenway or the Garden could find a spot, reserve it and pay for it from a phone.

Sounds great, but is “smaht pahking” really possible in a city known for its confusing parking regulations and even more confused drivers?

“If everything works out, this is going to be good for everybody, with less pollution, less fuel and less traffic,” said Christos Cassandras, a Boston University engineering professor who has developed his own smart parking app, which is even more advanced than the one Streetline uses.

One of the reasons Boston is so anxious to use a smart parking system is that the lack of parking is one of the major complaints cited by tourists and shoppers.

Research has shown that up to one-third of all cars driving around in a city are cruising the streets looking for parking spaces. The average time to find a space is about 10 minutes. That adds up to millions of gallons of wasted fuel, as well as increased air pollution.

But Cassandras said there are potential drawbacks to the Parker app. While it directs drivers to available spaces, it doesn’t tell them where the best ones are or allow them to reserve them, at least for now. This means it could create more congestion with drivers all competing for a few empty spots.

“It’s still putting pressure on the driver to make the final decision,” he said.

A number of other cities, including Washington, D.C., Los Angeles and San Francisco, already have been testing out the app, but this is the first time Boston has tried out the new technology.