Intelligent Transport Systems Sensor Technology for the Smart Roadside

By Lane Latto | May 17, 2013

Intelligent Transport Systems Sensor Technology for the Smart Roadside

The use of emerging technologies in traditional roadway systems can provide real-time traffic services to drivers through telematics and intelligent transport systems (ITS). The Smart Roadside system utilizes various sensors for driver assistance and traffic safety warnings.

Telematics are defined as in-vehicle systems that offer active safety and infotainment services as well as location and traffic information via wireless communication technologies. In many countries, a variety of in-vehicle telematics systems and intelligent transport systems (ITS) are already available, while new systems are being designed.

The US Department of Transportation, ITS Strategic Research Plan (2010–2014), IntelliDrive projects dealing with ICT and transportation convergence technologies, including vehicle-to-vehicle (V2V) interaction and vehicle-to-infrastructure (V2I) interaction, are concurrently underway.

The main focus of the ITS strategy is aimed at reducing travel time; easing delays and congestion; improving safety; and reducing pollutant emissions without the need for new roadway construction. ITS strategies that contain electronic surveillance, communications, and traffic analysis and control technologies bring about benefits to transportation system users and managers.

ITS sensors often serve as data-gathering elements of the system and therefore dictate operating characteristics, types of data provided, and installation requirements. There are two popular categories of sensors currently used in the Smart Roadside: infrastructure-based sensors and on-board diagnostics-based vehicle sensors.

Infrastructure-based sensors include pressure detectors, inductive loop detectors, magnetic detectors, ultrasonic detectors, microwave detectors, infrared detectors, and image detectors. These types of sensors utilize a part of the signal control and traffic operation in an ITS.

In contrast, vehicle sensors include GPS, automatic vehicle identification (AVI) using radio frequency identification (RFID) tags, and (on-board diagnostic) OBD-based vehicle sensors, which are connected to an in-vehicle network.

These data points are supplied by the controller area network (CAN) bus. Vehicle sensor data can be formatted as probe data or messages, which are processed, formatted, and transmitted to a smart road server for further processing in order to create a clear understanding of the current driving environment, providing the driver and fleet operators with valuable, real-time information regarding the vehicle.

Ultimately, this information will assist transportation managers in monitoring and managing transportation system performance. Some of the resulting actions that could come from effective processing of this data might be the adjustment of traffic signals, transit operations, or dispatching of maintenance crews or emergency services. This information could also help transportation agencies and fleet operators to manage crews and use resources as efficiently as possible.

As the vehicle itself is the initial component of the intelligent transport system, we must also address the signal control and traffic operation aspects of the operation. At the heart of these operations is the need for a universal interface and communications component.

The National Transportation Communications for Intelligent Transportation System Protocol (NTCIP) is a family of standards that provides both the rules for communicating (protocols) and the vocabulary (objects) necessary to allow electronic traffic control equipment from different manufacturers to operate with each other as a system.

To assure both manufacturer and user community support, NTCIP is a joint product of the National Electronics Manufacturers Association (NEMA), the American Association of State Highway and Transportation Officials (AASHTO), and the Institute of Transportation Engineers (ITE).

Applications for NTCIP are generally divided into two categories: Center-to-Field (C2F) and Center-to-Center (C2C). C2F normally involves devices at the roadside, communicating with management software on a central computer. C2C usually involves computer-to-computer communications where the computers can be in the same room, in management centers operated by adjacent agencies, or across the country.

Both the C2F and C2C applications require an initial interface for the signal and control components that have an installed NTCIP communications protocol. This interface circuit, as the example above portrays, has interconnect devices consistent with RS232 and RS485 protocols as well as Ethernet interfaces. These interfaces translate into applications for Subminiature-D PCB connectors as well as RJ45 PCB Jacks.

In addition, this circuit also provides for terminal block interfaces for various components such as traffic lights and other intersection-related devices.

The notion of a Smart Roadside is not exclusively an American notion. Many areas of the world have initiated similar and parallel initiatives.

In Europe, Cooperative Vehicle-Infrastructure Systems (CVIS) projects have been underway since 2006 and are supported by a grant from the European Commission. A precondition of the CVIS projects is that users of cooperative systems be made aware of these systems and understand how they can help drivers operate more safely, economically, and comfortably.

Driven by the Korean government, the SMART highway R&D project was launched in 2008 and should be completed by 2015. By Korean definition, a SMART highway is a future high-speed roadway that supports an intelligent and convenient driving environment by providing roadway, vehicle, environmental, and human information, enabling users to concentrate solely on their driving and therefore reduce accident rates.

As ITS proliferates globally, the demand for interface cards with their embedded interconnect devices will expand across all borders in significant volume.

Lane Latto
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