Principles of Transportation Economics
Intelligent transportation systems–formerly called intelligent vehicle-highway systems (IVHS)–are information technologies that, when implemented in vehicles, on roadways, or centrally, can lead to vast savings in journey time, improved driver safety and convenience, and significant reductions in energy consumption and pollution. Among the capabilities of current and future ITS technologies are the following: • Traffic can be managed on the main roadways of major metropolitan areas through (1) control of road junctions and access to major routes, (2) rapid detection of and response to incidents (e.
g. , accidents and heavy congestion), and (3) communication of advice to drivers and passengers about traffic conditions. In addition, automatic vehicle identification and toll collection open the way to variable pricing of roadway access (i. e. , pricing based on road congestion). • A wide variety of information systems can be available to travelers (e. g. , route guidance, nearby restaurants and other traveler facilities, travel time to the airport).
Drivers and passengers can receive certain information by means of either eye-level “heads-up” displays or voice synthesizers installed within the vehicle. • Drivers can be automatically alerted to the proximity of other vehicles or obstacles. Under some advanced ITS technologies, automatic steering and intervehicle spacing control both facilitate collision avoidance and dramatically increase highway throughput. • Commercial vehicle operators can receive regulatory documents (e. g. , permits and registrations) for multiple states in a single transaction.
They can also undergo automatic weight checking without having to stop. • Continuous monitoring of the physical state of the road itself–as well as of bridges, tunnels, and the like–with early warnings of deterioration or structural weaknesses can be carried out through a network of probes embedded in the physical infrastructure. Of course, it is important to emphasize that ITS is a collection of information technology concepts that can be installed incrementally and that will continue to be designed, limited only by engineering ingenuity.
In terms of objectives, some ITS systems aim to increase traffic distribution on existing roadways, while others aim to increase throughput by means of improved centralized traffic control and improved individual driver/vehicle control. Thus, we can identify three broad categories of ITS: traffic management systems, traveler information systems, and vehicle control systems. In the literature on ITS, these terms are often preceded by the word “advanced” to highlight the use of advanced technology in their implementation.
American efforts to implement infrastructure have always been dogged by the issue of whether the government or private industry should lead the initiative. This is a long-standing debate that has raged since the earliest days of the Republic when Albert Gallatin, the secretary of the treasury under President Thomas Jefferson, called for a ten-year, government-led plan to create a wide swath of roads and canals from north to south and east to west. Both state and federal governments were active until the rise of railroads, when sentiment turned heavily against government participation.
The debate was rekindled when the first highway programs were considered during the New Deal. Spearheaded by the government after a long debate over public versus private financing, public roads moved forward after federal government studies showed that there was little prospect for private financing of the entire network of freeways. These experiences and debates suggest that there is an under-appreciated historical record that demonstrates the willingness of our political institutions to support innovative efforts when substantial economic gains might be achieved.
They also suggest that some benefits of the recent move to privatization might be melded with an old-style push for government-backed infrastructure to create more “intelligent infrastructure” for the twenty-first century. ITS are expected to yield potent benefits when they are applied to current transportation problems. Just as the power of technology promotes major operational improvements in business, so too is it expected to bring about traffic congestion reduction, vehicle safety, economic benefits, environmental improvements, and driver convenience.
In addition, the indirect benefits of ITS may include economic stimulus to a number of sectors, including the creation of a new type of service industry that will provide information to people on the move. ITS benefits will accrue to three groups: individual travelers, specialized road users (e. g. , commercial trucking companies), and society in general. In assessing the value of information technology to roadway travel, these benefits and their impact must be considered. During the past fifteen years, car usage has been growing at double-digit rates whereas the growth in highway and road capacity has been relatively static.
For example, during the late 1980s the United States experienced a 22 percent increase in vehicle miles but only a 5 percent increase in urban freeway miles. This has resulted in the intolerable urban traffic congestion levels that we now face. An accident blocking one of three freeway lanes reduces capacity by 50 percent. A 20-minute blockage can waste 2,100 vehicle hours, back up traffic for almost two miles, and take two and a half hours to clear. Moreover, the problem is not unique to the United States. The Japanese have a major problem with congestion as well.
Speeds average less than 10 miles per hour during daytime hours over much of Japan’s metropolitan areas, even on expressways. Congestion is expected to worsen in the future. By 2008, it is estimated that there will be 253 million vehicles traveling 3. 16 trillion miles–that is, 40 percent more vehicles and 65 percent more traffic than we experience today ( Willis 1990). Because congestion does not increase in a simple linear fashion, these figures portend a serious problem. In this regard, the work day for commuters is expected to get longer and longer. This is one of the key driving forces for change in the transportation system.
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