Let it snow, let it snow, let it snow

When a snowplow driver spraying salt on frozen roads in Hyannis cracked the window of a parked car in March, state highway officials knew whom to blame. They looked up records from the Global Positioning System satellite network and found which contractor was plowing the road at that time.

They then referred the angry driver to him.

The incident is just one of dozens that have convinced state officials that GPS, used for the first time last winter, has been an unqualified success.

With GPS, originally used by the Department of Defense, the state can track every snowplow it sends out onto the roads. If they need extra plows or salt in a certain area, state officials can determine how best to get them there.

Another benefit: The technology can spot drivers who are off their routes, or not working.

''We're watching it in real time," said John Cogliano, commissioner of the Massachusetts Highway Department. ''We can see where the vehicles are. We know how many hours were spent plowing state-managed roads. We know every dollar spent on snow and ice operations was spent appropriately."

Massachusetts is the first state to test GPS for use on its snowplows, but a handful of other states are following the lead, Cogliano said.

And GPS has become increasingly common in a variety of business uses, from shipping packages to fixing electrical lines. In Boston, city officials want to use GPS technology on school buses, sparking resistance from the drivers union, which sees the technology as an invasion of privacy. A California company is even pushing parents to outfit their children with GPS watches, so parents can track them wherever they go.

But a year after GPS was put on the state's snowplows, most of the debate now hinges not on the technology's merit, but on how it will be implemented. Members of the Massachusetts Snow and Ice Contractors Association, who protested outside the State House and lobbied highway officials against GPS last year, now say they realize that it's here to stay.

Some snowplow operators say GPS's first year was plagued by problems, and that the system, which works via cellphones, was so complicated that many drivers could not figure out how to log on. The president of the Massachusetts Snow and Ice Contractors Association, Matthew Frazier, called GPS's implementation last year an ''absolute total failure."

He said he heard stories of GPS pinpointing a truck at a fishing pier in Gloucester -- even though it was plowing snow on Cape Cod. Another time, he said, GPS showed a truck going 110 miles an hour while plowing snow. More commonly, he said, drivers experienced problems logging on or logging off.

But in a sign of how much the debate has changed, Frazier also said he was optimistic that state officials have ironed out most of the kinks.

''We're really looking forward to this year's system," he said. ''Our relationship wasn't all that great this time last year. Things have really changed. We're really impressed with what we know of the system so far."

Cogliano, the highway commissioner, denied that there were any technical problems with GPS last year. He said any difficulties probably resulted from human error.

The state spent $55 million on plowing snow last year, largely to pay private contractors to plow state roads. With snow budgets always tight, Cogliano said, GPS will make sure the state is not wasting money.

Some drivers said they do not mind using GPS.

Fred Nava, owner of Fred Nava & Son in Kingston, who has plowed the roads for 37 years, said the GPS system is only a problem for people shirking their work.

''It doesn't really affect us unless you're doing something wrong," Nava said. ''Everyone who does what they're supposed to do has no problem with it."

Sasha Talcott can be reached at stalcott@globe.com.