HAMPTON -- Officials say the infamous five-mile backups at the Hampton tolls will be a thing of the past when work on New Hampshire's first "open road tolling" project is completed by mid June or earlier.

The $17 million project — where motorists with E-ZPass accounts will be able to drive through at highway speeds — is reported to be on schedule.

"The opening date is June 15 but we are aggressively trying to get it ready for Memorial Day," said Christopher Waszczuk of the state Department of Transportation.

Crews have already removed the structures from the center lanes of the toll plaza and the related section of the overhead canopy. They have also installed the new overhead gantry system that will support the open road toll technology.

The project entails converting the inner six lanes of the now 18-lane toll plaza to two northbound and two southbound open road tolling lanes with shoulders and a central median barrier.

With open road tolling, motorists with E-ZPass transponders will be able to travel through either the dedicated open road tolling lanes or the traditional lanes with toll takers. Officials hope when the project is completed it will eliminate congestion, especially during the summer months, when traffic can sometimes backup to the Maine and Massachusetts borders.

"For the most part, we expect during the summer time there will be enough capacity there to handle the peak volume of traffic that we experience there on the weekends," Waszczuk said.

The plaza will still operate conventional toll booths for cash-paying motorists, but the New Hampshire Department of Transportation anticipates a spike in the number of travelers choosing electronic payment.

Already, Waszczuk said, utilization of the E-ZPass is up 5 percent this year over the same period last year.

Currently, 58 percent of vehicles use E-ZPass at the Hampton Toll Plaza.

"This cutting-edge electronic tolling technology will make a huge difference for motorists and air quality," according to a press release from department Commissioner George Campbell. "The infamous five-mile backups at the Hampton tolls will be a thing of the past, even during the summer weekend peak hours."

Waszczuk said three contractors were involved in the project.

Continental Paving Inc. of Londonderry completed a $4.8 million project last year that included the widening of the plaza and ramp work.

The prime contractor, Pike Industries, is working on the actual open road toll project.

The state awarded a $2 million contract to Telvent, a Spain-based technology company, to design and implement a computerized toll system to track and charge vehicles moving through the toll zone.

Manuel Sanchez, Telvent's chairman and chief executive officer, previously said the open road tolling system will serve as a model for other toll plazas in and around New Hampshire.

To pay for the Hampton toll plaza project, the governor and Executive Council increased the I-95 toll fare by 50 cents for passenger vehicles and by $1 for dual-tire vehicles. The fare increases took effect July 1 of last year.