It’s a persistent dream of transportation professionals that vehicles on American roads and highways will be wirelessly connected to computerized systems that will boost safety and reduce congestion. The advanced communications networks that form such a system might, for example, inform drivers about to make a left turn that oncoming traffic is moving too fast to proceed safely, or perhaps send drivers a warning of an accident or of congestion ahead — a big improvement on the electronic highway signs that are often difficult to read or display outdated information. These systems could also help drivers sidestep gridlock by suggesting an alternate route; help locate and reserve a parking space; provide information that warns drivers of changing traffic patterns; automatically adjust the timing on traffic signals along the route; and reduce traffic during busy periods by dynamically assessing fees for driving on the most congested routes.
Such systems would do much to reduce the 43,000 traffic fatalities that occur each year at a cost of US$230 billion to the U.S. economy and to reduce bottlenecks that have turned some stretches of America’s highways and urban centers into virtual parking lots. The U.S. transportation infrastructure — as well as the transportation infrastructure in much of the world — is reaching the limits of its capacity.
Experiments to create intelligent highway systems are not new. The U.S. Department of Transportation (DOT) tested a system of road sensors in San Diego 10 years ago that used radar, lasers, and cameras to send real-time information to onboard computers that controlled braking, acceleration, and steering. Although groundbreaking, the program proved too intrusive for most drivers, who were just getting used to cruise control. Since then, other federal or state programs have tested similar systems, and auto manufacturers have tested such smart features as adaptive cruise control, which automatically adjusts speed so that the car maintains a safe distance from the vehicle in front of it.
Although certain elements of an intelligent road system have proven successful, such as traffic signal systems that automatically control the flow of cars to allow emergency vehicles to safely navigate busy intersections, none of the experiments or component systems has yet blossomed into full-fledged, connected, system-wide networks. One reason is financial: Local governments lack sufficient funding to launch and maintain smart roadways alone and without access to sophisticated and well-drawn cost-benefit analyses, and state and municipal authorities are unable to produce a good economic argument to raise enough money for these systems. In addition, confusion lingers over which business models will ensure that systems will be financially viable, can be maintained over the long term, and will operate seamlessly across the nation.
Progress toward this vision has been slower than many advocates would like: They note that it’s been five years since the DOT secured rights from the Federal Communications Commission to use the Dedicated Short Range Communications (DSRC) 5.9 GHz radio band exclusively for safety applications, including collecting real-time information from moving vehicles. But there actually has been movement. By the spring of 2008, tests of the concept will take place in Michigan and California. They will, among other things, capture weather-related data from vehicles based on windshield wiper use, wheel traction, and braking efficiency and then broadcast this information instantaneously into other vehicles or post it on road signs.
Meanwhile, stakeholders — including the DOT, state authorities, automakers, radio and computer equipment manufacturers, telecommunications services providers, and toll road operators — are watching three sets of initiatives that may shed light on which technologies and business models make the most sense as a national public policy. Any of these experiments (each is intended for a different purpose and sponsored by a different entity) could become the basis for full-fledged intelligent highway programs: