Elaine Petrone of Raleigh wants to know why she and her husband got bills in the mail from the N.C. Turnpike Authority, illustrated with photos of their license plates, for trips on N.C. 540 near Research Triangle Park.

The bills were for $0.00.

"I didn't see any signs that say this is a toll road," Petrone said. "It's a waste of resources to be running that thing you're not collecting tolls on, and sending out bills for zero dollars."

The bill is a bleak warning from the N.C. Turnpike Authority to drivers on this section of 540: It's free now. But get ready to pay.

Between now and early August, thousands of drivers can expect to receive these baffling bills for zero dollars and no obvious sense.

This three-mile leg of the 540 Outer Loop in western Wake County, from N.C. 54 to N.C. 55, has been a toll-free ride since it opened in July 2007. But, with the consent of state and federal officials, it later was incorporated into the 18.8-mile Triangle Expressway - as the link between two new sections that otherwise would have been built as separate toll roads.

In January, drivers started paying tolls electronically on the first 3.7 miles of TriEx, an extension of N.C. 147 through RTP between I-40 and 540.

Toll collection starts in early August for this part of 540, and also for six new miles that will extend 540 south from N.C. 55 to U.S. 64 in Apex. The final leg of the six-lane expressway, reaching farther south to N.C. 55 at Holly Springs, opens in December.

Quick Pass discount

More than 14,000 drivers have N.C. Quick Pass electronic transponders in their cars, and the Turnpike Authority has deducted about $125,000 in TriEx tolls from their accounts so far.

Another $60,000 in tolls has been billed to the owners of cars without transponders, who received invoices based on photos of their license plates. Some bills are for as little as 45 cents, and the Turnpike Authority has actually received checks for that tiny amount.

The agency wants TriEx drivers to use the N.C. Quick Pass. So it gives transponder users a 35 percent break on the toll rate. These no-charge bills serve as direct-marketing messages for drivers on a free road about to become a toll road.

"Those folks that are traveling 540 now, they're the ones that are receiving the zero-dollar invoices," said Barry Mickle, operations director for the Turnpike Authority. "It's telling you to get out there and sign up for your N.C. Quick Pass. So that your future tolls ... will be reduced by 35 percent."

Bigger bills loom

When TriEx grows longer, the toll bills will grow larger, and Mickle will have fewer reporters asking him to justify spending about 50 cents, including a 35-cent stamp, to send out a bill for 45 cents.

But until then, he might hear from drivers complaining about those zero-dollar toll bills.

"I have no intention of paying tolls," Petrone said. "I don't want to give my credit card number to the state and have a transponder, and I don't want to pay double because I don't have a transponder."

Srinivas Saraswatula of Raleigh hasn't received a bill yet. But a few nights ago he saw the lightning-blink flash of a Turnpike Authority camera recording every license number - including his - on this section of 540.

"It's interesting that they've decided on this intrusive way of collectingmoney," Saraswatula said. "Who else gets access to all this information? Google knows enough about me already."

Make contact: 919-829-4527 or bruce.siceloff@newsobserver.com. On the Web at twitter.com/Road_Worrier and blogs.newsobserver.com/crosstown. Please include address and daytime phone.