INTELLIGENT VEHICLES

Steve Shladover

Even when cars were still young, futurists began thinking about vehicles that could drive themselves, without human help. Perhaps the best known of these conjectures was the General Motors Futurama, the hit of the 1939 New York World's Fair. Now, at the start of the new century, it's worth taking a fresh look at this concept and asking how automation might change transportation and the quality of our lives.

Consider some of the implications of cars that could drive themselves.

We might eliminate the more than ninety percent of traffic crashes that are caused by human errors such as misjudgments and inattention.

We might reduce antisocial driving behavior such as road rage, thereby significantly reducing the stress of driving.

The entire population, including the young, the old, and the infirm, might enjoy a higher level of mobility without requiring advanced driving skills.

The luxury of being chauffeured to your destination might be enjoyed by all, not just the wealthiest individuals.

Fuel consumption and pollution might be reduced by smoothing traffic flow and running vehicles close enough to each other to benefit from aero dynamic drafting.

Traffic-management decisions might be based on firm knowledge of vehicle responses to instructions, rather than on guesses about the choices that drivers might make.

The capacity of a freeway lane might be doubled or tripled, making it possible to accommodate growing demands for travel without major new construction, or, equivalently, today's level of congestion might be reduced, enabling travelers to save time.

Is it feasible?

This is now a realistic prospect. With advances in technology we can readily visualize your trip on an automated highway system.

Imagine leaving work at the end of the day and needing to drive only as far as the nearest on-ramp to the local automated highway. At the onramp, you press a button on your dashboard to select the off-ramp closest to your home and then relax as your car's electronic systems, in cooperation with roadside electronics and similar systems on other cars, guide your car smoothly, safely, and effortlessly toward your destination. En route you save time by maintaining full speed even at rush-hour traffic volumes. At the end of the off-ramp you resume normal control and drive the remaining distance to your home, better rested and less stressed than if you had driven the entire way.

Although many different technical developments are necessary to turn this image into reality, none requires exotic technologies, and all can be based on systems and components that are already being actively developed in the international motor vehicle industry. These could be viewed as replacements for the diverse functions that drivers perform every day: observing the road, observing the preceding vehicles, steering, accelerating, braking, and deciding when and where to change course.

Observing the road

Researchers have developed a road-reference and sensing system that makes it possible to determine accurately a vehicle's position and orientation relative to the lane's center. Cheap permanent magnets are buried at four-foot intervals along the lane centerline and detected by magnetometers mounted under the vehicle's bumpers. These meters provide the in formation used by the vehicle's control computer to determine its exact position of the vehicle.

Other researchers have used computer vision systems to observe the road. These are vulnerable to weather problems and provide less accurate measurements, but they do not require special roadway intallations, other than well-maintained lane markings.

Observing preceding vehicles

The distances and closing rates to preceding vehicles can be measured by a radar or a laser rangefinder. Both technologies have already been implemented in commercially available systems in Japan and Europe. The laser systems are currently less expensive, but the radar systems are more effective at detecting dirty vehicles and operating in adverse weather conditions. As production volumes increase and unit costs decrease, the radars are likely to find increasing favor.

Steering, accelerating and braking

The equivalents of these driver muscle functions are electromechanical devices installed in the automated vehicle. They receive electronic commands from the onboard control computer and then apply the appropriatesteering angle, throttle angle, and brake pressure by means of small electricmotors. Early versions of these devices are already being introduced intoproduction of vehicles, where they receive their commands directly from thedriver's inputs to the steering wheel and pedals. These decisions are beingmade for reasons largely unrelated to automation. Rather they are associated with reduced energy consumption, simplification of vehicle design, enhanced ease of vehicle assembly, unproved ability to adjust performance to match driver preferences, and cost savings compared to traditional direct mechanical control devices.

Deciding when and where to change course

Computers in the vehicles and those at the roadside have different functions. Roadside computers are better suited for traffic management, setting the target speed for each segment and lane of roadway, and allocating vehicles to different lanes of a multilane automated facility. The aim is to maintain balanced flow among the lanes and to avoid obstacles or incidents that might block a lane. The vehicle's onboard computers are better suited to handling decisions about exactly when and where to change lanes to avoid interference with other vehicles.

Remaining challenges

There remain a number of difficulties to be overcome. These are mainly technical, but there are in addition a number of nontechnical challenges that need to be addressed. These involve issues of liability, costs, and perceptions.

Automated control of vehicles shifts liability for most crashes from the individual driver (and his or her insurance company) to the designer, developer, and vendor of the vehicle and roadway control systems. Provided the system is indeed safer than today's driver-vehicle-highway system, overall liability exposure should be reduced. But its costs will be shifted from automobile insurance premiums to the purchase or lease price of the automated vehicle and toll for use of the automated highway facility.

All new technologies tend to be costly when they first become available in small quantities, then their costs decline as production volumes increase and the technologies mature. We should expect vehicle automation technologies to follow the same pattern. They may initially be economically viable only for heavy vehicles (transit buses, commercial trucks) and high-end passenger cars. However, it should not take long for the costs to become affordable to a wide range of vehicle owners and operators, especially with many of the enabling technologies already being commercialized for volume production today.

The largest impediment to introduction of electronic chauffeuring may turn out to be the general perception that it's more difficult and expensive to implement than it really is. If political and industrial decision makers perceive automated driving to be too futuristic, they will not pay it the attention it deserves and will not invest their resources toward accelerating its deployment. The perception could thus become a self-fulfilling prophecy.

It is important to recognize that automated vehicles are already carrying millions of passengers every day. Most major airports have automated people movers that transfer passengers among terminal buildings. Urban transit lines in Paris, London, Vancouver, Lyon, and Lille, among others, are operating with completely automated, driverless vehicles; some have been doing so for more than a decade. Modern commercial aircraft operate on autopilot for much of the time, and they also land under automatic control at suitably equipped airports on a regular basis.

Given all of this experience in implementing safe automated transportation systems, it is not such a large leap to develop road vehicles that can operate under automatic control. That should be a realistic goal for the next decade. The transportation system will thus gain substantial benefits from the revolution in information technology.