The more your car knows, the safer you—and everyone around you—will be, or so goes the thinking.

The network linking a car’s major systems—engine, transmission, brakes, suspension, and so on—already does many things. It helps cars correct skids before they happen, brake better, avoid tailgating, warn of unsafe lane changes, hold you securely in place in a collision, and call for assistance if you crash. Someday soon, cars will network to other cars and roadside data systems to spread the word about congestion, road conditions, and accidents. And they’ll access travel-related Internet services.

A new family of four IEEE standards is bringing that day closer, by ensuring that car and roadside infrastructures can communicate with each other. These standards could do for cars and vehicular transportation what the popular IEEE 802.11 wireless standards have done for laptops and networking.

The IEEE 1609 suite of WAVE Communications standards, developed for the U.S. Department of Transportation (DOT), covers the underlying architecture for WAVE (Wireless Access in Vehicular Environments). The WAVE protocol uses the dedicated short-range communications band, at 5.9 gigahertz. Three of the standards in the suite have been approved for trial use, and one is pending.

The first, IEEE Std. 1609.2, approved in June, covers methods of securing WAVE messages against eavesdropping, spoofing, and other attacks. The second, IEEE Std. 1609.1, released in October, deals with managing multiple simultaneous data streams, memory, and other system resources. The third, IEEE Std. 1609.4, approved in November, primarily covers how multiple channels—including control and service channels—should operate.

IEEE Std. 1609.3, which covers WAVE networking services and protocols, and is an extension (802.11p) to the IEEE 802.11 wireless networking standard covering WAVE-mode transmission, is under development.

The Intelligent Transportation System Committee of IEEE’s Vehicular Technology Society is the sponsor of the WAVE standards. Funding comes from the DOT, and the Federal Communications Commission has allocated a 75-megahertz swath of the 5.9-GHz band for WAVE.

WHY WAVE? The WAVE system, once in place, would be designed to make driving safer and easier. Several times each second, WAVE-equipped cars will transmit information to other cars and to roadside transceivers about their location, speed, acceleration or deceleration, brake status, windshield wiper operation, and more. Such information is already circulating within cars equipped with GPS, electronic speedometers, antilock brakes, and other sensor-based systems.

The roadside transceivers could eventually be installed at every traffic light and freeway interchange along major roads, “and anywhere there have been lots of accidents,” says IEEE Member Lee Armstrong, who is the editor of IEEE Stds. 1609.1, .3, and .4. The roadside units will share information with passing vehicles and with safety, highway, and traffic-control authorities.

To monitor traffic better, vehicles with WAVE could double as traffic reporters. They’ll also sense ambient temperature and road conditions, enabling highway authorities to deploy snowplows, for example, even before they’re needed. And the roadside units could warn drivers away from hazards and congestion. “You’ll also be alerted when a traffic light’s about to change, and be warned if someone’s running through it,” Armstrong says.

None of the information coming from cars will identify the vehicle it comes from. “We’re building privacy in, from the ground up,” says IEEE Member Doug Kavner, who chaired the security subgroup for IEEE Std. 1609.2. To mask their points of origin, for example, WAVE-equipped cars will transmit only limited data until they’ve traveled a certain distance from their starting points, Kavner says. For even more privacy, WAVE radios will change their local Internet Protocol (IP) and medium access control addresses periodically.

Drivers will receive information about road conditions, red lights, and hazards from cars 300 to 500 meters ahead on highways, and 100 meters ahead in cities. Emergency vehicles, equipped with longer-range (1-kilometer) WAVE systems, will be able to warn vehicles ahead to let them pass and to control traffic lights to give them the right of way.

Vehicle manufacturers must decide how to use WAVE data, how to present the data to drivers, and what automotive systems to control. The emphasis will be on driver alerts, including visual, audible, and tactile warnings. A warning of an impending accident will be fed to pre-crash systems, such as those now found on some luxury cars. These systems do such things as pre-tension seat belts, prepare brakes for an emergency stop, and tilt reclined seats upright.

A WAVE radio could alert the driver to traffic and other road conditions.

NATIONWIDE Once widely adopted, the WAVE infrastructure could provide a single, nationwide system for paying tolls, time-of-day road charges, and other usage fees. It might also be used to pay for gas and parking, though the DOT does not currently contemplate doing that. Like today’s piecemeal toll-tag and credit-card systems, such uses could compromise driver privacy and will be switched on only in cars whose drivers opt for them. Data on traffic and road conditions, however, will be sent automatically and anonymously.

More intrusive uses, such as tracking cars that speed or ignore stop signs and traffic lights, probably would not be allowed in the United States, both for privacy’s sake and lest they discourage car owners from adopting the system.

The auto industry, the IEEE, and the DOT hope their cooperation will ensure that when vehicles with WAVE roll off the assembly line, “there will be infrastructure to communicate with,” a DOT representative says. Even so, the road infrastructure might lag behind WAVE installations in cars, because responsibility for roads is spread among the states and countless local traffic, transit, and safety authorities.

“Who will pay and who will orchestrate is under discussion,” says Kavner, the security subgroup chair, “though it seems safe to assume that there will be federal involvement and funding.”

HOW FAR OFF? Highway tests of the WAVE system are scheduled to begin soon. Electronics manufacturers are prototyping WAVE radios, and the auto industry, which has been involved with the technology for several years, is developing ways to build the radios and their antennas into cars. The government and the auto industry are expected to decide whether to implement the system by the end of next year. Cars with WAVE may come off the assembly line in about 2011.

Tests so far have uncovered no technical problems. WAVE is built on existing technologies, such as the IEEE 802.11 chipset and an adaptation of IP version 6. However, the new standards are for trial use and may well need revision before they are permanently adopted.

First, of course, the system has to work, Kavner notes. “No decisions have been made about deployment, and no one has deployment in their current budget,” he says. “But the DOT, the auto industry, and other groups are pouring a lot of effort and money into WAVE. They really want to make it happen.”