Case 17: NTTA converting to AETC

Location:	Texas, USA
Client:	North Texas Tollway Authority (NTTA)
ITP:	Electronic Transaction Consultants Corporation (ETCC)
Application:	All Electronic Toll Collection (AETC)
Product:	Idris AT600
Project:	Conversion of > 300 lanes to AETC

Background: Progress and growth demand change. Throughout its history, the North Texas Tollway Authority (NTTA) has embraced change to benefit its customers and has implemented sophisticated technology, including pioneering some of the earliest open-road tolling facilities.

History: NTTA’s Wycliffe Avenue mainline toll plaza on the Dallas North Tollway (DNT) is a highly travelled, 32-mile, six-lane tollway at the southern end of the DNT that serves as a major traffic conduit from three rapidly growing North Texas counties, through the bustling northern suburbs and central Dallas, to provide a major gateway to the prime business, government, and entertainment areas of downtown. Principally a commuter route, the DNT serves some of the fastest-growing cities in the United States, and the region has experienced explosive growth since its first plaza, the Wycliffe Avenue mainline plaza, opened to traffic in June 1968. Currently the Wycliff Plaza processes on average 2.5 million transactions – 200,000 more than it did in 2007.

The new NTTA gantry

Project detail: In December 2010, the NTTA completed one of its most ambitious and beneficial acts – a strategic move to convert its entire facilities (more than 300 lanes) to all-electronic toll collection. Moving toll collection to all-electronic raised the issue of how tolls could be collected from vehicles without TollTags. Without an alternative solution, all vehicles without a TollTag would be treated as violators which could result in major customer relations issues for NTTA. The existing system was modified as this was the most efficient solution to the problem. NTTA worked with its system integrator, ETC Corporation to design and implement the needed changes. Through this approach, the ZipCash® video tolling system was born.

How it works: Toll customers are identified by either a vehicle-mounted transponder, such as a TollTag, or if this is not present, a picture of the vehicle licence plate is taken and the customer receives a bill for the toll. Intended as a temporary solution for the Wycliffe plaza during construction the result turned out to be the impetus for NTTA’s move to AETC.

NTTA’s existing Idris AT600 consists of Idris smart loops which register a vehicle traveling over the loop site and track it for the duration of its time within the site. All the data from the loop signature is collected by Idris and processed to provide a Per Vehicle Record (PVR). At the same time as Idris is collecting the data to create each vehicle's PVR, it is also triggering the camera’s to capture the front and rear license plates with a precision of +/- 30cms (1ft) from the nominated trigger point, noting the lane and time of each read.

As a vehicle's PVR is being created, Idris analyses the position of vehicles over the site with respect to all ALPR reads which might be associated with the vehicle of interest. It then uses the spatial information available to match the vehicle it is processing to the correct ALPR record, associating the corresponding licence plate to this vehicle. If no acceptable ALPR record is found for a vehicle, a trigger is sent to the camera to take an overview picture of the vehicle for billing purposes. The Idris system required no adjustments for the upgrade to AETC to take place. The functionality and capabilities of Idris are designed to enable continued development and progression of a tolling system.

Results: AETC provides a solution that will deliver benefits for years to come. As road authorities embrace the free flow revolution, they need to be sure the technologies they have installed can support the change in business rules. The move to AETC has reduced congestion and improved safety levels. In addition, the move to AETC and its resulting reduction in air pollution levels was a factor in the NTTA being awarded the IBTTA’s 2009 Excellence Award for Social Responsibilities. The project will deliver long-term benefits for an entire region. Benefits which have far reaching effects on financial and planning issues faced by authorities. As road authorities embrace the free flow revolution, knowing the existing technologies they have in place support the change in business rules is a highly advantageous feature.