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THE ONGOING SUBTLE REVOLUTION

A technology revolution is now quietly and thoroughly transforming the nation’s transportation system from the inside out: Vehicles and guideways look much as they have, but inside changes have been occurring rapidly. In personal vehicles, microchips regulate engines; new technologies control car and truck braking; and electronic tuning ensures cleaner engine burn. Vehicle components, materials, and systems are safer than a decade before, and are still improving. Flame-retardant materials have replaced flammable padding in cars, buses, trains, and airplanes, and plastics have replaced other structural materials. Highway and airport pavements are more durable, cheaper, and easier to maintain. Communication, information, and navigation systems integrated into passenger cars are enabling smarter and safer personal driving. Aircraft continue to become quieter, more efficient and environmentally friendly, and electronic applications and tracking systems have revolutionized the freight industry. And, despite the increasing level of technical sophistication, the costs of many transportation system components -- particularly those linked to electronics -- are coming down.

Enabling Technologies for Transportation

The continued development and maturation of several groups of technologies could together dramatically transform transportation as we know it over the next several years, especially in a nation with a robust economy. These technologies will enable the United States to build a transportation system that can provide better, more efficient and environmentally friendly service adapted to individual needs and preferences of all its users, at an affordable cost. They include the following:

• Improved understanding of human performance and behavior, which has highlighted the critical role fatigue plays in many crashes and incidents. It has led to the development of techniques to identify performance degradation and countermeasures which can improve vehicle operator alertness. A better understanding of the ways people interact with automated systems and information displays is leading to system control and operations improvements. Work on human performance also makes possible transportation design changes to reduce the likelihood of operator error, and enhance system safety and efficiency.
• New computer, information and communications systems, which have already transformed the way the transportation system is planned, designed, developed, maintained, managed and controlled. Computers regulate and monitor gas and oil pipeline flows and safety. On the highways, video-monitored intersections and synchronized traffic lights are already improving safety, capacity, and efficiency of urban and corridor travel. Positive Train Control systems have a similar potential to improve railroad safety and efficiency. Users with computer terminals already can conduct instant travel planning, reservations, ticketing, and rerouting through Internet connections for many kinds of trips and travel. Electronic tagging technology is used for diverse applications such as automated toll collection on turnpikes and the automatic identification of freight train consists. Fiber optic networks have proliferated, and may accelerate developments in the fast-growing field of photonics, which seeks to create computers and other machines that use light (photons) rather than electric current to transmit and process information.
• Advanced material and structural technologies, which have led to new, environmentally benign, and corrosion resistant materials (like geosynthetics and fiber-reinforced composites) used in crash-resistant vehicles and improved guideways. Other physical infrastructure improvements include durable recycled pavements; and composite wrapping materials to reinforce older structures. New kinds of superconducting and magnetic materials may make high speed ground transportation more attractive, and improved high-temperature alloys will lead to supersonic, hypersonic and orbital craft.
• Energy, propulsion and environmental engineering advances, which provide options to deliver improved transportation service that is cheaper, more energy efficient, and environmentally friendly. A variety of new powerplants for personal vehicles which have entered operation on a test basis, including fuel cells, advanced batteries and alternative-fueled engines, will have particularly broad impacts. The use of alternative fuels like natural gas can reduce emissions of nitrogen oxides, energy costs, powerplant maintenance costs, and transfer payments overseas. New turbine-powered locomotives now under development are expected to accelerate implementation of high-speed rail corridor services throughout the country. New technology turbojet/ turbofan, ramjet and supersonic combustion ramjet, and linear aerospike engines may transform aviation during the same period.
• Sensing and measurement technologies, which are making transportation safer and more reliable by detecting obstacles to moving vehicles, weather patterns, changes in development resulting from transportation, and emissions of greenhouse gases and other system products. Non-destructive evaluation (NDE) techniques using advanced sensor approaches will become more important as the physical infrastructure of the transportation system grows older, and has to be replaced.
• Analysis, modeling, design and construction tools, which will enable system planners to experiment with alternative system configurations, predict the performance of those systems, assess the impacts of those systems, and develop design improvements in one integrated process. A new generation of decision support models will improve targeting of transportation investments. Structural and crash performance "testing" may be done at lower cost with simulation models.

In some cases two or more trends re-enforce each other. For example, the emergence of "smart structures" and evolution of "intelligent materials" with built-in sensors (eventually of sub-microscopic size) will improve safety, and reduce the possibility of sudden failures. High temperature alloys, new propulsion concepts, and upgraded air traffic control may make feasible new kinds of airliners, which fly higher and faster than the current generation of planes. Likewise, many advances in computers, information technology, telecommunications, navigation, materials, structures, propulsion, sensing and human factors have been occasioned or accelerated by space transportation applications.

In addition, our present $300 billion telecommunication industry is becoming inextricably linked with the transportation system. Transportation moves people and physical objects, while communications moves data and ideas. The two systems link and network billions of users across the globe constantly. Again, the two reinforce each other’s growth. GPS-aided in-car navigation and other satellite-based services to serve multi-modal transportation users become possible with real-time communication links to the satellites. Geographic information systems (GIS) will utilize real-time data from satellite positioning systems and other kinds of remote sensors, and will be a major resource for planners of future transportation systems to draw on. As these systems and improvements come on-line, they set the standards of performance for future systems to match and exceed.

The Small Frontier – Nanotechnology

In the longer term, advances in nanotechnology, which involves working with substances at the atomic or molecular level, will impact all of these technology areas. The size scales being considered in nanotechnology are much smaller than ever dealt with in manufacturing or engineering: for example, a human hair is about 10,000 nanometers thick.

Rice University characterizes nanotechnology in three distinct, but highly interdependent, areas:

1. "Wet" nanotechnology, which is the study of biological systems that exist primarily in a water environment.
2. "Dry" nanotechnology, which derives from surface science and physical chemistry, focuses on fabrication of structures from carbon, silicon, and other inorganic materials.
3. Computational nanotechnology, which permits the modeling and simulation of complex nanometer-scale structures. ⁷

Nanotechnology will provide a variety of tools to build the transportation system for the twenty-first century. For example, advances in nanotechnology may make possible carbon-based fibers which are 100 times stronger than steel, at only one-sixth the weight. ⁸ Among the breakthrough applications that might be forthcoming in transportation from nanotechnology applications are the following: ⁹

• Nanotechnology will yield advanced materials that will allow for longer service life and lower failure rates. Among the key applications are nanocoating of metallic surfaces to achieve super-hardening, low friction, and enhanced corrosion protection; "tailored" materials for infrastructure and vehicles; and "smart" materials that monitor and assess their own status and repair any defects resulting from fatigue, fire, etc.
• Nanotechnology has great potential to support advanced communications that maximize the benefits of intelligent transportation systems and obviate the need for some travel altogether; sensors that continually monitor the condition and performance of roads, bridges, and other infrastructure; and "brilliant" vehicles that can avoid crashes and improve operator performance.
• New materials developed through nanotechnology will permit the ultra-miniaturization of space systems and equipment, including the development of "smart," compact sensors; minuscule probes; and microspacecraft. Applications include economical supersonic aircraft; low-power, radiation-hardened computing systems for autonomous space vehicles; and advanced aircraft avionics.
• Nanotechnology has the potential to reduce transportation energy use and its impacts on the environment. Applications include nanosensors to monitor vehicle emissions and trigger traps for any pollutants observed; nanoparticle-reinforced materials that replace metallic components in cars; replacement of carbon black in tires with nanoparticles of inorganic clays and polymers, leading to tires that are environmentally friendly and wear-resistant; and carbon-based nanostructures that serve as "hydrogen supersponges" in vehicle fuel cells.

Breakthroughs in nanotechnology also should make possible quantum computers, which will exceed the limits on the speed and miniaturization of conventional computers by exploiting the quantum nature of reality. Conventional computing machines are limited by the manufacturing capability to create smaller and smaller circuits and chips, and to dissipate the heat which is generated as the device operates. Quantum computers offer a way around these obstacles. ¹⁰

A Japanese team has already demonstrated a nanometer-scale superconducting qubit (quantum bit, the fundamental elements quantum computers use to work) chip. The device combines the properties of a quantum dot -- a box so small that adding an electron is a significant change -- with the quantum purity of the superconducting state, where electricity flows without resistance. At this stage, the qubit maintains its properties for only a very short time, up to about two nanoseconds. The next steps towards viable computers are to extend the limited lifetime of the qubits, and to connect qubits to make simple logic gates and circuits. ¹¹

Quantum computers should far exceed the speed and efficiency of conventional machines. They will handle computation with new algorithms (computational procedures or rules) based on quantum principles. Preliminary areas of application under discussion including factoring large numbers, searching of extremely large databases, and simulation of other quantum-mechanical systems. They may be used to design other nano-scale manufacturing and mechanical systems. ¹²

Another possibility is the emergence of biocomputers, which would use DNA or other biological materials to encode numerical values and data, and use chemical reactions to generate outcomes. Techniques for synthesizing, reading, cutting and splicing, and classifying DNA sequences have already been developing in the context of research with recombinant DNA. Computers based on such approaches theoretically could perform any calculation that any conventional computer could, operating on a "massively parallel" basis, with huge amounts of memory available, and with little energy consumption. Some experts view such molecular scale machines as longer-term options, and do not expect them to enter service in the near term. ¹³ However, a Hewlett-Packard team has already created a molecular-based logic gate – a basic building block of all computers – and are working on new processor production technologies, and chemical processors that might supersede today’s silicon computer chips. ¹⁴

In summary, breakthroughs in nanotechnology could make possible fabrication of materials at the molecular scale, self-repairing structures, totally new types of computers, and accelerated emergence of true intelligent systems. They are truly "wild cards" for system forecasts to consider.

Impacts of the New Technologies

Despite some pessimism about unanticipated impacts, the public’s expectations about the impacts of technology are quite positive. Their concerns focus on a few key issues, including urban growth, environmental impacts, potential loss of privacy, etc. For example, the transportation enterprise is essential for economic growth, but currently accounts for approximately one third of the nation’s fossil fuels use, and contributes about one third of the nation’s greenhouse gases. Expanding data systems speed many transactions, but raise fears about the erosion of personal privacy. Nevertheless, there seems to be an abiding faith that responsible technological improvements, coupled with needed structural changes in the transportation system, will maintain and expand future mobility without compromising other key elements of America’s quality of life.

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