70 THE FIVE-YEAR OUTLOOK 



Table 2— Freight Haulage 

 (in billion-ton miles) 



MODE 



197? 



1985 



1990 



2000 



Highway ' 

 Air 

 Rail 

 Water 



Pipeline 

 Total 



' Assumes commercial and government vehicles; excludes personal 



trucks. 



Source: R.E. Knorr and Marianne Miller Projeclions of Direct Enerf^y 



Consumption by Mode: 1975-2000 Baseline. ANL/CNSV-4. Argonne. 



111.: Argonne National Laboratory. 1979. 



a U.S. population of 250 million, the per capita average 

 would be 20,000 passenger miles and almost 21,000 ton- 

 miles. Under that assumption, the average annual increase 

 in per capita passenger transportation capability between 

 1975 and 2000 would have to be about 2 percent and that 

 for freight transportation about VA percent over the next 

 20 years (NRC-16). Thus, while transportation is ex- 

 pected to continue to grow on a per capita basis, that 

 growth is expected to be slower during the rest of the 

 century than in the immediate past. 



Alternatives to increased transportation capacity do 

 exist. Increased decentralization of production into small- 

 er, more self-reliant communities is one such alternative 

 for reducing demand, thus decreasing capacity problems, 

 and that possibility would be facilitated by expanding 

 communications capabilities {Outlook I). But, since such 

 changes are accomplished slowly and are measured in 

 multiples of decades, transportation demands will almost 

 certainly continue to grow during the rest of the century. 



DEALING WITH CAPACITY LIMITATIONS 



In the face of a need for increased transportation capacity. 

 it also is likely that the entire U.S. transportation system 

 will be encountering increasing limits on its carrying 

 capacity during the next 5 years. For example, the high- 

 way system is already showing signs of wear (Outlook I). 

 Programs for pavement resurfacing, restoration, re- 

 habilitation, and bridge replacement have the potential to 

 stem the problem. However, costs will be substantial. 

 particularly because we are lagging so far behind in main- 

 tenance (TRANS). Ironically, the situation has been exac- 

 erbated by our success in improving the fuel economy of 

 motor vehicles, since their increased use has led to a 

 decrease in highway maintenance funds derived from fuel 

 taxes. 



Development of paving substitutes from nonpetroleum 

 derivatives that will be competitive with asphalt and port- 

 land cement is a key area where research and development 

 can contribute to highway improvement and maintenance. 

 In addition, technologies for detecting highway flaws are 

 a preventive alternative that could reduce maintenance 



costs and help relieve capacity constraints on the highway 

 systems that are due to failures and repair and mainte- 

 nance outages (TRANS). 



Increasing highway congestion is another serious con- 

 cern. Currently available control technologies can deal 

 effectively with low concentration flows of highway traf- 

 fic, but high-density congestion remains a problem. Alter- 

 natives are emerging, however, that could extend our 

 capability to control highway congestion. One is the 

 emerging technology of ramp metering signalization for 

 highways. In the much longer term, more general automa- 

 tion of highway travel may become an effective flow 

 control procedure both for reducing congestion and for 

 improving safety. 



Air transportation will also face increasing capacity 

 problems during the next several years as traffic growth 

 begins to reach airport capacity (NRC-16). The problem 

 has been averted so far with the development of larger 

 aircraft, but that approach is nearing its limit. One alterna- 

 tive solution is provided by current developments in ad- 

 vanced air traffic control, which will improve the produc- 

 tivity of the U.S. commercial air transport system 

 (NRC-16; TRANS). 



The success of various future energy strategies for the 

 United States (see Section II-E) will require substantial 

 modifications in the capacity of transportation systems to 

 move energy sources. In particular, if the use of coal is to 

 be greatly expanded — both for direct use and as a source 

 of synthetic fuels — improvements will be required in its 

 distribution modes. At present, rail, water barge, and 

 trucking handle 63 percent. 11 percent, and 12 percent of 

 the coal traffic in the United States, respectively, with 

 other modes accounting for only 3 percent. (The remain- 

 ing 11 percent of the coal is used for onsite power genera- 

 tion at mines.) Analysts believe that of those three trans- 

 portation modes, railroads offer the best combination of 

 flexibility and cost for domestic transportation. Antici- 

 pated needs for the next decade will, however, require a 

 good deal of expansion in the carrying capacity of rail- 

 roads in the West, and an expansion as well as an overall 

 improvement in the quality of railroads in the East." The 

 use of slurry pipelines, in which crushed coal mixed with 

 water is carried, offers an economically attractive alterna- 

 tive for rail transport for distances up to 300 or 400 miles. 

 Available water may be a limiting factor, however, par- 

 ticularly in the Rocky Mountain West. Meanwhile, re- 

 search is proceeding on the flow behavior of the coal- 

 water mixture (ENERGY). 



The movement of coal also requires traffic flows on the 

 U.S. waterway system, which is constrained by capacity 

 limits. In particular, our port systems are currently unable 

 to handle the storing and loading of the volume of coal 

 destined for ocean transport. That is a particularly impor- 

 tant concern for the future, since the United States, with 

 an estimated 30 percent of the world's coal reserves, could 

 gain considerable trade advantage as an exporter of coal 

 (NRC-16: TRANS). 



