Robert Morehead Jr. gets ready to hang another E-ZPass sign at a toll booth in Newport in January. It costs drivers $4 each way if they pay with cash.

The Providence Journal / Steve Szydlowski

NEWPORT — The new electronic toll-collection system used on the Pell Bridge, E-ZPass, is increasingly popular among Rhode Islanders, offering both convenience and a way to pay tolls that is less expensive than cash.

However, those benefits have a hidden cost.

Privacy advocates argue that the technology motorists have been encouraged to use has punched another hole in people’s privacy, this time by tracking where they’ve been.

Using E-ZPass involves a transponder, or “tag,” mounted on the car and a prepaid account linked to the tag, from which the system deducts tolls as they are incurred. The toll data is linked to the vehicle owner’s name, address and other personal information.

Privacy advocates object that electronic toll collection means that drivers leave an electronic record, down to the minute, wherever they pay a toll. In Rhode Island, that means there’s a record of the date and time when they crossed the Pell Bridge, the state’s only toll plaza.

But the record also includes where and when they pay tolls anywhere E-ZPass is honored. That area stretches from Maine to Virginia to Illinois.

“That can very easily be used to track people’s location history,” said Lee Tien, an attorney with the Electronic Frontier Foundation, a San Francisco nonprofit that supports civil liberties in the high-tech arena. “It’s something people just don’t think about, that the system knows where you are and when you pay.”

Could E-ZPass data allow the police to trace a vehicle across states, for example from Rhode Island to Virginia, the southern-most E-ZPass state?

“Ideally, yes,” said James Crawford, executive director of the E-ZPass Interagency Group, which coordinates the network from Atlantic City. He said the data is available in two or three days, after the transactions have cleared the system.

Steven Brown, executive director of the Rhode Island Affiliate of the American Civil Liberties Union, said that the toll data is a disturbing gap in citizens’ privacy.

He also said that there’s no law protecting the records from disclosure to anybody who wants them.

Legislation the ACLU pushed to shield the data from civil lawsuits and to require that police get a court order to obtain it has passed the General Assembly. However, the legislation has not been transmitted to Governor Carcieri, who has not indicted whether he will sign it.

That leaves decisions about who uses the data to the Rhode Island Turnpike and Bridge Authority, which implemented E-ZPass in December.

The authority’s “customer agreement” with those who use E-ZPass makes no privacy commitment. However, both authority board Chairman David A. Darlington and Executive Director Earl J. “Buddy” Croft III say they won’t release the data until a judge directs them to.

“No information comes out of the authority unless there’s a court subpoena,” Croft said.

It’s not clear what the authority’s written E-ZPass privacy policy is.

Crawford said there is one, but, asked for a copy said, “I’m not going to give it to you.”

Privacy advocates say that as long as the data exists, it will be used, or misused, for purposes other than toll collection.

For example, tag readers can be located at places other than toll plazas. That’s already happening elsewhere, with sensors placed along highways in the San Francisco Bay Area to measure traffic. The data helps drivers decide which highway to take and estimate how long the trip will take.

California authorities say they take elaborate measures to keep the information private. Skeptical drivers, meanwhile, can keep information from being read from their tags (when they aren’t paying tolls) by putting the tags in shielding envelopes.

Brown is also concerned that keeping the data for long periods only encourages its misuse. He said there’s no reason for the E-ZPass agencies to keep it for longer than is needed to collect tolls. Crawford said that member agencies normally keep the data for about two years.

Law-enforcement officers in some states are already aggressively trying to use data obtained from the electronic toll-taking system.

“In New York, the police have a whole system set up where they can get a court order almost immediately,” Crawford said. “They’ve got people sitting in courtrooms so they can take the information, get a court order and fax it back.”

Toll data also has been used in civil and criminal court cases elsewhere. In divorce cases, the records can puncture claims about who was where, and when. Massachusetts prosecutors used E-ZPass records to trace Sean Fitzpatrick, a suspect in a 2006 double murder case. The police said he stole a pickup truck whose owner had an E-ZPass tag, leaving a trail through three tolls driving toward the murder scene, and then through the same ones leaving it.

In court, however, toll data can help either side. Michael A. DiLauro, director of training and legislation at the Rhode Island Office of the Public Defender, said the agency is looking into using those records to help defend its clients, and also into deciding how to defend against data used by the prosecution.

MOTORISTS in East Coast states, including Rhode Island, have been encouraged to use E-ZPass because it is convenient — there’s no more rummaging for money while driving toward the toll booth. It combines tolls into a single, monthly bill and can reduce congestion at toll plazas.

With the previous token system, customers could buy tokens in bulk with cash for 83 cents each, a deep discount, and still cross the bridge anonymously. The cash toll was $2.

A Rhode Island resident with an E-ZPass tag still pays only 83 cents per trip, but tokens are gone.

It’s still possible for a driver to cross the bridge anonymously, but that means paying cash. The cash toll doubled on Sept. 8, to $4.

Here’s how the electronic, E-ZPass System works.

When a vehicle passes through a toll plaza, a tag reader electronically records information such as account number, location and time, to the minute. That information is linked to the car owner’s personal data, including address, phone number, and the vehicle’s make and model. The toll is deducted from the owner’s prepaid account, whether the car is at the Pell Bridge or one of 24 other E-ZPass toll booths across the Northeast. Together, the agencies have 18 million tags in circulation.

Reciprocity is a key element: the E-ZPass agencies collect each others’ tolls. When a Rhode Islander incurs a toll on the New York Thruway, a record of the transaction is transmitted to the Rhode Island authority, which deducts the money from the driver’s account and passes it along to the New York State Thruway Authority.

Drivers can maintain a balance on their own or let the authority automatically debit their credit cards.

Rhode Island drivers are adopting the new system quickly. Darlington, the authority chairman, said that 70 percent of Pell Bridge users are now paying with E-ZPass.

SOME STATES have offered a system that allows anonymous use of the electronic toll system.

For example, the Texas Department of Transportation offers an “unregistered” version of its TxTag account that can be opened without providing a name, address or other personal information. The agency says the accounts can be replenished with cash or a money order. Early this month, there were 46,112 active anonymous TxTag accounts out of a total of 407,982, according to Karen Amacker, a spokeswoman for the Texas DOT.

Crawford said there is an anonymous tag, called “E-ZPass on-the-Go,” that is offered in some states but not yet in Rhode Island.

E-ZPass on the Go is sold in stores for cash and includes a tag often carrying $25 in credit. That offers privacy, at least to start with. However, much of the purchase price is actually a deposit on the tag itself. In some cases, only $15 of the $25 may be available for tolls. Using on-the-go tags for privacy alone means throwing away a substantial part of their value, although Crawford said that may be offset by any discounts for tag use.

Darlington said the Rhode Island authority considered looking into E-ZPass on the Go but put it off until the basic E-ZPass system was running smoothly.

“There’s nothing in our rules that would prevent any agency from doing that,” Crawford said, referring to Texas’ anonymous accounts, but he said no E-ZPass agency is doing it.

Crawford said practical considerations stand in the way of permitting similar accounts here.

“It is extremely expensive to handle walk-in payments,” he said. “That is a major reason agencies don’t want them.”

Also, if Rhode Island offered Texas-style anonymity and a customer’s account balance ran out while driving in another state, the Rhode Island authority could be stuck with the unpaid bill.

He said, though, that technology is likely to change things, and he expects that “we will begin to see ways for anonymous payments to be made electronically.”

SO FAR, the electronic data collected in Rhode Island can only place a vehicle at the Pell Bridge.

However, there will probably be more Rhode Island toll plazas, and they will almost certainly use E-ZPass.

The Turnpike and Bridge Authority is already looking at reinstituting tolls on the Mount Hope Bridge to pay repair bills. Also, a study commission appointed by Governor Carcieri to find money to fix roads and bridges recommended instituting tolls on the state’s major highways. The authority study will look into that, too.

Darlington said that E-ZPass will almost certainly be the mechanism to collect new tolls. Using an incompatible system would destroy the convenience of paying tolls throughout the region with one monthly bill.

blandis@projo.com