Yaws

Traffic congestion caused 3.7-billion hours of travel delays, wasting 2.3-billion gallons of gasoline and $63 billion in 2003, according to the 2005 Urban Mobility Report issued by the Texas Transportation Institute. That's missed meetings, late arrivals to the office and cold suppers on the table. What's a nation laden in debt to do to help alleviate the problem, short of spending trillions on new road projects to accommodate the millions of vehicles added to the infrastructure each year? Experts say businesses should promote telecommuting, using the Internet and telephone for meetings, along with utilizing technology to monitor traffic flow, reducing accidents and improving throughput. The latter solution is the one General Motors is focusing on, including what's called vehicle-to-vehicle communications technology (V2V).

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A test drive in a Cadillac CTS equipped with V2V demonstrated two key uses of the system: lane change/blind spot warning and forward collision avoidance with auto-brake. During the lane change test, my green CTS cruised along the GM test track in Milford, MI, at a comfortable 40 mph, while a silver CTS rode alongside directly in my blind spot. When I tried to make a lane change, using the turn signal, a yellow warning light flashed in the side-view mirror, providing a clear indication that a vehicle was present. A second test was done traveling at the same speed although this time the silver CTS approached the left side of the vehicle at a high rate of speed. Using the turn signal to indicate a lane change, the V2V system received a signal from the approaching silver CTS and immediately illuminated the warning light and sent a gentle vibration through the left side of the driver's seat, indicating a potential collision could occur, prompting me to stay in my lane. Once the lane change tests were complete, it was on to the collision avoidance round. Here, the first test involved the previously mentioned silver CTS, along with a black Suburban. As the silver CTS cruised along at 35 mph, the driver performed an abrupt stop, forcing the Suburban to make a quick lane change. The V2V system immediately recognized the silver CTS was moving slowly and flashed a warning light on the dashboard of my test CTS and sent a gentle vibration to the front of the driver's seat. Additionally, the silver CTS' rear brake and reverse lamps began flashing like strobes, providing an added visual warning, all which allowed for quick stopping before a rear-end collision happened. The next test was the most disconcerting of them all: Auto-brake. During the test, I approached the silver CTS, which was at a dead stop, at approximately 35 mph. As I neared the rear of the silver CTS, its rear tail lamps and reverse lights began blinking, to get my attention. In addition to which, a warning light lit on the dash of my car, and the front of my seat began vibrating. And as I kept approaching the silver CTS, the braking system of my car took over and automatically brought the vehicle to a stop before I could rear-end the other car. It was hard not to stomp on the brake as my car approached the silver CTS, but I managed to keep my composure ... OK, so I tapped on the brake slightly.

HOW DOES V2V WORK?

The V2V system uses GM's OnStar and Stabilitrak technology*, along with a simple antenna and computer chip, to detect the position and movement of similarly-equipped vehicles, up to a quarter-mile. Signals between vehicles are communicated over a WiFi network using the 80.211p protocol, which has been assigned by the Federal Communications Commission for wireless access in vehicles because of its improved range and speed on the dedicated 5.9 GHz band. "You have got your GPS information on OnStar and you've got your wheel-spinning rates and yaws and all the other information you get from Stabilitrak and we take those two pieces of information and we put the mathematical algorithms together that not only tell you where the car is, but gives you dead reckoning insight on where its headed. That's where we think we have some intellectual advantage," says Larry Burns, GM's vice president-research and development and strategic planning, who envisions the system reaching production within the next five to 10 years. He compares the system to transponders used in the airline industry, where most civil aircraft are required to have transponders that communicate where they are located during flight. "You can think about a future world where all cars have to have a transponder. Some of the cars would take advantage of that in an active sense, saying if I know where every car is I have got this sixth sense on the vehicles and make my driving task easier, safer and more effective."

V2V FOR ALL?

The V2V system is unique to GM, but the auto maker is interested in working with Federal regulators and competitors to make the system ubiquitous. "We will work with all the other stakeholders to make this work," Burns says. GM believes the vehicle-to-vehicle communications approach to reducing traffic congestion and accidents is a more realistic way to improve vehicle throughput on highways, as opposed to other programs that call for installing magnetic pegs on roadsides and transponders in road signs. "The path to a smart transportation system is putting the intelligence on the vehicle and not in the roadway system. If you can communicate everything that you need to know about location and not have to do that with roadway infrastructure, that's a benefit," Burns mentions. Plus, the additional antenna and sensor are minimal additional cost--Burns says it's no more than the cost of the average cell phone. Compare that to spending trillions to put magnetic pegs every few feet on the 8,315, 121-miles of roadways in the U.S. and you can see why it would be easier to spend a couple of bucks for an antenna and sensor on each car.

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The V2V system also marks another step on the path to autonomous vehicle travel, where the vehicle will be able to propel itself without input from the driver. It's a dream the industry has had for many years, but the technology has proven expensive and illusive, until the development of V2V, according to Burns. "When you see something like V2V and combine that with adaptive cruise control, you ask yourself 'How far are we from autonomous driving in a highway situation?' Technologically, we are not that far away." While the technology may be there, will drivers be willing to take their hands off the wheel and read their morning paper while going to work? Wait, many already do that.

*Stabilitrak is an integrated stability control system made up of three sensors that keep the anti-lock brake system and traction control computer apprised of steering wheel angle, lateral acceleration and yaw rate and selectively applies individual front brakes to keep the car on its intended course.

By Kevin M. Kelly, Senior Editor

COPYRIGHT 2005 Gardner Publications, Inc.
COPYRIGHT 2006 Gale Group