The county also has a contract with Xora Inc., a California-based mobile technology company, which provides cell-phone GPS applications for county social workers. That program cost $7,600 to start up, plus $8,000 in monthly costs. The program started for safety reasons, to help track social workers who may walk into dangerous situations, he said.

Rising fuel costs and environmental requirements are driving public agencies' interest in GPS, said James Wright, president and CEO of Fleet Counselor Services, an Arizona consulting company that works with government clients.

"When this first started a couple years ago, the general thought was they wanted to keep track of their employees to monitor their productivity, especially with things like plowing snow, street-sweeping, household refuse pickup — where there's a planned route," Wright said. "Now, it's blossomed into reducing fuel consumption, monitoring idle time, on top of improving productivity."

NexTraq, the county's vendor, works with private companies including construction, distribution and landscaping firms, said Steve Pitsos, vice president of operations for the firm. It's seeing growing interest from the public sector, including local governments, school districts and police departments. Baltimore County is NexTraq's biggest government client.

"For them, it's all about accountability, efficiency and reliability because they're trying to be good stewards of taxpayer dollars," Pitsos said.

John Ripley, president of the Baltimore County Federation of Public Employees, said his union would closely monitor how county management uses the system. Ripley said he also wonders how the county can afford the technology.

"If the system is used to unreasonably discipline or take action against employees, then we do have a problem," he said, adding that any technology may not always provide accurate results.

The devices are common for local governments in the Baltimore metropolitan area.

In Baltimore, the Department of Transportation was the first city agency to use GPS, with a pilot program starting in 2004, spokeswoman Adrienne Barnes said. Officials hope to expand the program, she said.

The city's Department of Public Works has the technology in more than 700 vehicles and is awaiting funding to equip more, spokesman Kurt Kocher said.

Howard County has been using GPS technology for its snow removal operations since 2000, spokeswoman Karen Spicer said. From November to March, the county uses the GPS system on about 144 vehicles.

GPS can help make sure workers are not misusing their time, said Wright of Fleet Counselor Services. "Sometimes it is Big Brother, and sometimes Big Brother's needed," he said.

Stradling says Baltimore County's system isn't focused on tracking people for disciplinary reasons, but rather is part of County Executive Kevin Kamenetz's efforts to do more with less by taking advantage of technology.

"We're not being punitive here. We're trying to help you get your work done," Stradling said. "A big majority of the county employees have no problem with it at all."

He added that technology can help employees perform their jobs more efficiently as government resources shrink. This year, more than 300 county employees retired under an early-retirement incentive that was meant to eliminate positions without laying anyone off.

The county has 7 percent fewer employees than it did last year.

"Every agency that's in the field is delivering some kind of service," Stradling said. "The folks that stayed behind after the retirements want to deliver the service."