72 THE FIVE-YEAR OUTLOOK 



airlines transport more than 300 million passengers an- 

 nually. The U.S. rail system is the largest in the world, 

 with more than 300,000 miles of track. It is projected that 

 in the highway mode alone, however, more than 50,000 

 Americans will die in traffic accidents in 1981. Addi- 

 tionally, while motor vehicle fatalities account for the 

 largest portion of transportation-related deaths, there also 

 are losses due to air. rail, and water accidents (TRANS). 



In choosing among options for future improvements in 

 the transportation system, implications for safety will 

 have to be one of the major underlying considerations. 

 The safety of individual technologies can be assessed 

 through a variety of scientific and technological means, 

 and there will be increased needs for those kinds of 

 assessments. iji the ccRiiF.g years (TRANS) (see also Sec- 

 tion I-E). 



It is worth noting that most technological effort has 

 focused on postcrash survivability and injury reduction 

 rather than on accident prevention. As the United States 

 moves toward increased use of smaller vehicles, such 

 strategies will become more costly and less effective. A 

 good deal of information relative to automotive safety 

 gains could come from human behavior studies 

 (NRC-16). Additionally, two technologically oriented op- 

 tions now being explored primarily for nonhighway trans- 

 portation that also could have fruitful implications for 

 automobile traffic safety are described below. 



The innovative use of radionavigation, radiolocation, 

 radiocommunication, and computer systems provides op- 

 portunities for improving both the safety and the 



efficiency of air and water transportation by expanding the 

 capabilities of and improving access to sophisticated navi- 

 gation, warning, and traffic control systems. For example, 

 with anticipated increases in air and water traffic, systems 

 to provide both for specific coverage in highly developed 

 geographical areas and for wide area coverage will be 

 needed. Additionally, new developments in electronic 

 communications and computer microprocessor technol- 

 ogy are lowering the costs of and facilitating improve- 

 ments in advance warning systems. New radar tech- 

 nologies soon will provide dramatic improvements in 

 capabilities for detecting and issuing warnings about se- 

 vere weather conditions and will also provide improved 

 weather information for air traffic and surface vessel con- 

 trol (TRANS). 



The convergence of computer and communications 

 technologies may also provide opportunities for transpor- 

 tation safety improvements through automation. Some 

 experience with such automated systems is already avail- 

 able in mass transit and air traffic control. Human opera- 

 tors cannot, however, be entirely eliminated from any 

 control system, be it related to transportation, manufactur- 

 ing, or power plant operation. Indeed, the training and 

 skills required of human operators increase as control 

 systems become more sophisticated. Therefore, human 

 factors research to provide a better understanding about 

 the interface between humans and machines may be one of 

 the most important needs related to transportation safety 

 (TRANS). 



REFERENCES 



1. U.S. Bureau of the Census. Slalislical Ahstrcul of the United Stales . 

 lOOlh edition. Washington. D.C.: U.S. Government Printing Oftice, 

 1979. Comparable figures for 1965 were 4,400 passenger-miles per 



person and 8,500 ton-miles per person. The average annual growth rates 

 between 1965 and 1975 were 2.4 percent for intercity passenger travel 

 and 1.64 percent for intercity freight. 



2. National Academy of Sciences. Energy in Transition: 1985-2010. 

 San Francisco; W.H. Freeman, 1980, pp. 195-197. 



I. Agriculture 



The U.S. agricultural enterprise is a major contributor to 

 the economic and social well-being of both this country 

 and the world. It currently provides food for more people 

 than ever before, while employing a constantly decreasing 

 proportion of the labor force. For example, each Amer- 

 ican fanner now produces enough food for himself or 

 herself and 59 other people, a significant rise from 29 in 

 1970 and just 6 in 1900 ( AAAS-8). In addition, American 



agricultural products are a mainstay of the food supplies of 

 many other countries. In fact, exports of agricultural prod- 

 ucts constitute over 20 percent of the total value of Amer- 

 ican exports, a situation that has clear short-term benefits 

 (lA). However, the capacity of the American agricultural 

 enterprise is limited. There could be long-term problems 

 associated with the world's dependence — and our own — 

 on American agricultural exports, including overexploita- 



