RALEIGH — The N.C. Turnpike Authority signed a $5.9 million contract Tuesday for technology that will enable the state to collect tolls electronically on the 18.8-mile Triangle Expressway.

No cash-collection tollbooths are planned for TriEx, now under construction in Research Triangle Park and western Wake County. The state's first modern toll road will open in RTP in 2011 and in western Wake in 2012.

Dallas-based TransCore, a unit of Roper Industries, will provide car-mounted trans ponders for motorists who pay tolls by maintaining debit accounts with the turnpike authority. Electronic sensors will record toll-road trips.

Drivers without transponders will be billed at a higher rate for tolls, based on photos of their license plates.

"We are proud that North Carolina will have one of the most technologically advanced toll operations in the nation," state Transportation Secretary Gene Conti said. "The implementation of this wireless system will provide motorists with seamless travel by allowing them to pay tolls at highway speed."

The contract also will enable North Carolina to collect electronic tolls from drivers who have E-ZPass transponders and debit accounts with turnpike agencies in northeastern states, and from those with transponders that use different technology in Florida, Texas and other southern states.

North Carolina expects to use similar electronic-payment technology for two toll roads planned near Charlotte and a toll bridge planned on Currituck Sound.

bruce.siceloff@newsobserver.com or 919-829-4527