CONCORD, N.H. (AP) – The E-ZPass system that will soon make it easier to pay tolls in New Hampshire will make it easier to track people’s movements, privacy advocates warn.

State officials say strict policies are in place to prevent that, and stress that E-ZPass will be voluntary. They also say the system will reduce traffic congestion and put off the need to expand the current toll plazas.

“We’ve reached a capacity level of expanding toll plazas in New Hampshire … and traffic volumes continue to grow from year to year,” said Albert Almasy, E-ZPass program manager for the state Department of Transportation.

Almasy said E-ZPass-only lanes can accommodate more than 1,300 vehicles an hour compared with 450 vehicles for a lane with a toll attendant.

New Hampshire will begin using the E-ZPass system later this year. Maine motorists enrolled in the system began using it two months ago.

The system uses transponders to collect toll information and cameras to monitor compliance. That raises concerns about whether data such as names and addresses could fall into the wrong hands, such as a stalker pursuing a victim or a divorce lawyer looking for dirt.

“The primary thing to keep in mind with an E-ZPass is basically you’re enabling a tracking system,” said Jordana Beebe of the Privacy Rights Clearinghouse, a nonprofit based in California. “We would strongly caution before the program is implemented, that there be a very robust privacy policy developed around its deployment.”

Kara Ross, spokeswoman for ACS State and Local Solutions of Washington, D.C., said that has been done.

“No one can get access to an account except for that account owner. Law enforcement doesn’t have access to it, government doesn’t have access to it. In order for anybody to have access to that data, they have to be subpoenaed,” she said.

ACS will handle customer service and violations in New Hampshire. It has similar management contracts in New Jersey, New York, Maryland, Delaware, South Carolina and California.

Almasy said New Hampshire has taken additional steps to protect privacy. The cameras to monitor compliance will photograph license plates of vehicles that don’t pay, not the people inside.

E-ZPass customers will be able to monitor their accounts on a Web site using a personal identification number.

Almasy also said New Hampshire’s E-ZPass data will not include people’s personal information.

“All that’s on there is a vehicle classification code, whether its a car, truck, etcera, and account information,” he said. He said he and one other state official will be the only ones with access to the ACS database that could identify people.

State Rep. Neal Kurk said lawmakers ensured that E-ZPass records would be used for billing purposes only. But the Weare Republican said he is sure law enforcement and parties to lawsuits will go after the data.

“I have no doubt that the information will be subpoenaed by a variety of people in legal cases to prove that the husband was in fact out on the highway cheating on his wife, or in a murder case, which has already happened in a number of cases in the New York area, to prove that the individual and his car had passed through the … tollbooth at a particular time when he claimed to have been at home.”