It is not an exaggeration, but a simple statement of fact, that the interstate highway system is an engine that has driven 40 years of unprecedented prosperity and positioned the United States to remain the world's pre-eminent power into the 21st century.

While it is not typically thought of in this way, the system is in reality a gift from one group of people --- highway users --- to the nation as a whole, which has reaped a gain of at least $6 in benefit for each $1 spent in construction. And that's just the beginning --- there are additional benefits such as higher employment rates and greater economic opportunity that are simply beyond quantification. Fortunately, the group of people who paid for the interstate highway system is sufficiently large that it's difference from the nation as a whole is virtually without distinction. But it is a worthy difference to keep in mind as a backdrop for public policy deliberations over future funding of highways.

This report provides an assessment of the manifold benefits of the interstate highway system. Research by leading transportation authorities and standard statistical methods have been used to estimate the impacts of the interstate highway system. The imperative for upgrading the interstate highway system and other super-highways is described and shown to be readily affordable within the capability of present highway user fee revenue.

The interstate highway system has contributed mightily to the economic growth and quality of life in America. The interstates and other super-highways will continue to contribute to economic growth and improved quality of life if necessary investments are made. In large measure, the interstate highway system has democratized mobility in the United States, providing virtually all Americans with the ability to move quickly to any destination within their communities and to travel throughout the nation, inexpensively, and at whatever time or date they desire.

America is a nation on wheels --- they benefit from a freedom of mobility that is unrivaled anywhere in the world. A substantial portion of that mobility is attributable to the Dwight D. Eisenhower System of Interstate and Defense Highways, which celebrates its 40th anniversary in 1996. The interstate highway system, the largest public works program in history, has had an enormous impact on the nation. The interstate highway system has positively influenced economic growth, reduced traffic deaths and injuries, provided substantial benefits to users, and been a crucial factor in the nation's defense.

Background

Early Planning: As automobiles began to democratize mobility in America in the 1920s and 1930s, it became increasingly clear that greatly improved highways would be needed to accommodate the demand. "Super-highways,"

NOTE: The term "super-highway" is used to denote a controlled access (grade separated) roadway with at least four lanes of traffic separated by direction. Super-highways may be toll roads or free (freeways). In most nations, including the United States, "free" super-highways are not really free, in that their construction, maintenance and patrolling costs are paid by highway user fees. grade separated roadways with four lanes of direction-separated traffic, first appeared in the New York City area parkways that opened in the 1920s.

The interstate highway system was first approved by Congress in 1944, but it was not until 1956 that a comprehensive program was enacted to build the system. By this time, it had become apparent that post-war affluence had produced a huge increase in highway demand and that rapidly expanding highway freight movements required a much improved system. Further, in the volatile Cold War era, national defense provided a primary justification for developing a super-highway system to accommodate the quick and efficient movement of military equipment and personnel.

Authorization of the Interstate Highway System: On June 29, 1956, President Eisenhower signed the Federal Aid-Highway Act of 1956, which authorized the interstate highway system (later formally named the Dwight D. Eisenhower System of Interstate and Defense Highways). The Act authorized 41,000 miles of high quality highways that were to tie the nation together. Later, congressional action increased the length to 42,500 miles and required super-highway standards for all interstate highways.

The system was to be completed by 1975. It was conceived as a "pay as you go" system that would rely primarily on federally imposed user fees on motor fuels --- the federal user fee per gallon of gasoline was increased by one cent. The federal user fees would provide 90 percent of the cost of construction with the balance provided primarily by state user fees. The interstate highway system would incorporate approximately 2,000 miles of already completed toll roads.

High standards were adopted for the interstate highway system. Access to all interstates was to be fully controlled. There would be no intersections or traffic signals. All traffic and railroad crossings would be grade separated, requiring the construction of more than 55,000 bridges. Interstates were to be divided and have at least four wide traffic lanes (two in each direction) and adequate shoulders. Curves were to be engineered for safe negotiation at high speed, while grades were to be moderated, eliminating blind hills. Rest areas were to be conveniently spaced. Each interstate was to be designed to handle traffic loads expected 20 years after completion.

The states were soon underway with construction. As time passed, it became clear that the goal of system completion by 1975 would not be achieved. But by 1960, more than 10,000 miles were opened. By 1965, 20,000 miles were opened, and by 1970, 30,000 miles were open to traffic. And by 1980, 40,000 miles were complete. While some segments remain to be completed, more than 42,700 miles of interstate highways are now opened to traffic. The interstate highway system serves virtually all of the nation's large urban areas and serves 49 states (all but Alaska). Despite this broad expanse, the interstate highway system represents just over one percent of the nation's road network.

NOTE: Much of the information in this section ("Background") is from Richard F. Weingroff, "A Partnership that Makes a Difference," Public Roads (Washington DC: United States Department of Transportation, Federal Highway Administration, Summer 1996) and "Development of the Interstate Program," in America's Highways: 1776-1976 (Washington, DC: United States Department of Transportation, Federal Highway Administration, 1976).

NOTE: There have been additions to the system beyond the 42,500 authorization.

NOTE: Some highways in Alaska have been eligible for receipt of federal interstate funding, but Alaska contains no highways that are formally designated as a part of the interstate standard system.).

Performance of the Interstate Highway System

There have been tremendous changes in America since authorization of the interstate highway system in 1956. Population has increased by 70 percent, but employment has increased by more than 100 percent. The percentage of the nation's population that is employed has increased by nearly one-third in 40 years, reflecting a far higher rate of female participation in the work force. Household size has declined significantly. These factors combined to increase travel demand at a far greater rate than had been expected. And much of this increased travel has been on the interstate highway system.

The interstate highway system is the "work horse" of the nation's highway system. Representing just over one percent of the nation's highway system mileage, the interstate highway system carries nearly one quarter (23 percent) of all roadway traffic, --- more than 20 times its one percent share measured in mileage (1), and more than 60 times as many person miles as all passenger rail services (Amtrak and urban rail) (2).

NOTE: Unless otherwise noted, "highway system" refers to the system of all urban roadways in the United States (urban, intercity, and rural).

NOTE: A person mile is one person traveling a mile. For example, a car with a driver and no passengers produces one person mile per each vehicle mile traveled. A car with a driver and two passengers produces three person miles for each vehicle mile traveled.

NOTE 1: Calculated from data in 1994 Highway Statistics (Washington, DC: United States Department of Transportation, Federal Highway Administration, 1995).

NOTE 2: Calculated from data in National Transportation Statistics 1996 (Washington, DC: United States Department of Transportation, Bureau of Transportation Statistics, 1996), 1994 Highway Statistics and National Transit Database 1994 (Washington, DC: United States Department of Transportation, Federal Transit Administration, 1996)..

The interstate highway system has a much higher density of use than other components of the nation's surface transportation system. The interstate highway system carries nearly 60,000 daily person miles per route mile, 26 times as many person miles per route mile as all other roads (including low usage rural roads), and 22 times as many person miles per route mile as intercity rail (Amtrak) and urban rail combined.

Each year, nearly one trillion person miles are carried on the interstate highway system --- a figure equal to providing trips around the world for 37 million people --- more people than live in Pennsylvania, Illinois, and Ohio combined. In its 40 years, more than 17 trillion person miles have been traveled over the interstate highway system.

NOTE: Assumes vehicle occupancy on the interstates equals that of the entire highway system. This is the equivalent of:

• Nearly three trips around the world for each American.

• A trip to the moon for all of the people living in California, New York, Texas, and New Jersey --- nearly 75 million people.

• Three light years of travel through space --- nearly three-quarters of the distance to the nearest star outside the solar system (Alpha Centauri).

The interstates highway system in intercity and rural travel: The value of the interstate highway system may be most obvious in rural and intercity travel. For the most part, rural and intercity interstate travel is uncongested, permitting highly efficient traffic movement. Rural and intercity interstates provide a large measure of mobility, representing nearly 24 percent of all surface rural and intercity transportation --- 60 times that of passenger rail (Amtrak).

NOTE: Calculated from data in National Transportation Statistics 1996 (Washington, DC: United States Department of Transportation, Bureau of Transportation Statistics, 1996) and 1994 Highway Statistics.

Rural and intercity interstates also play a crucial role in freight transportation. It has been estimated that 45 percent of the nation's large truck (tractor-trailer) operations are on the interstate highway system.

NOTE: Benefits of Interstate Highways (Washington, DC: United States Department of Transportation, Federal Highway Administration, 1983).

Interstate highways have generally reduced travel times by 20 percent or more between cities. For example:

NOTE: Travel time comparisons from analysis of "United States Mileage Chart" and "Driving Distances and Driving Times" in American Automobile Association maps of the United States (Heathrow, FL: American Automobile Association: 1954, 1955 and 1996).

• Travel time between Seattle and Portland, Oregon has declined by nearly 25 percent.

• Travel time between Cleveland and New York City has declined by a third.

• Travel time between Atlanta and Birmingham has declined by nearly 40 percent.

• Travel time between Chicago and Minneapolis has declined by nearly 25 percent.

The time advantage of the interstates remains clear even today, when interstate and non-interstate corridors are compared.

• The average speed from Harrisburg to Albany, which is served by interstates, is more than 20 percent greater than from Harrisburg to Buffalo, which is not served by an interstate highway.
  NOTE: Travel time comparisons from analysis of "Highway and Driving Times Map," Rand McNally 1996 Road Atlas (Skokie, IL: Rand McNally Company, 1996).

• Travel time from Sacramento to Salt Lake City, served by an interstate, is 1.5 hours less than virtually the same distance from Phoenix to Salt Lake City, which includes a major gap without an interstate.

• Average travel time from Springfield, Missouri to Alexandria, Louisiana, which is not served by an interstate, is more than 40 percent longer than Springfield to Dallas, which is served by an interstate.

The interstate highway system in urban travel: The positive role of the interstates in the nation's urban areas is often overlooked or even discounted. In the early stages of interstate planning (1940s and early 1950s), proposed programs omitted cities from the system, limiting the role of the interstates to intercity transportation. The urban interstates were added to the system at the insistence of urban interests.

The interstate highway system provides crucial mobility in urban areas. The interstate highways provide a backbone transportation system that expedites urban trips for automobiles, buses, and trucks, while reducing traffic congestion on non-interstate arterials.

Even in New York City, which relies on non-highway (urban rail) transportation to a far greater extent than any other U.S. metropolitan area, the interstate highway market share (measured in person trips) is nearly double that of the region's sprawling rail system. In other urban areas, the interstate highway system is even more important, with interstate market share exceeding that of rail transit by more than thirty times.

NOTE: Estimated from data in 1995 Highway Statistics and National Transit Database 1994. Average urban interstate vehicle occupancy is estimated at 1.65, based upon analysis of data in the 1990 National Personal Transportation Survey and 1994 Highway Statistics.

• The interstate highway system made less expensive land more accessible to the nation's transportation system and encouraged development.

• The travel time reliability of shipment by interstate highway has made "just in time" delivery more feasible, reducing warehousing costs and adding to manufacturing efficiency.

• By broadening the geographical range and options of shoppers, the interstate highway system has increased retail competition, resulting in larger selections and lower consumer prices.

• By improving inter-regional access, the interstate highway system has helped to create a genuinely national domestic market with companies able to supply their products to much larger geographical areas, and less expensively.

Each of these cost reducing impacts have made both labor and capital more efficient and this has encouraged business expansion, new investment, and job creation.

Through the years, various estimates have been made of the contribution of the interstate highway system to the economy, generally finding that the interstate highway system has more than paid for itself in improved commercial productivity.

NOTE: See for example, Benefits of Interstate Highways (Washington, DC: United States Department of Transportation, Federal Highway Administration, 1970) and Benefits of Interstate Highways (Washington, DC: United States Department of Transportation, Federal Highway Administration, 1983).

NOTE: M. Ishaq Nadiri and Theofanis P. Mamuneas, Contribution of Highway Capital to Industry and National Productivity Growth (Washington, DC: United States Department of Transportation, Federal Highway Administration, 1996).

Using the results of this research, it is estimated that the interstate highway system is now producing approximately $14 billion.

NOTE: In 1996 dollars, based upon year of construction expenditure. Throughout the balance of the report all financial data is in 1996 dollars, unless otherwise noted. in annual producer cost reductions.

NOTE 1: Estimated based upon data in Nadiri and Mamuneas. A production cost decrease factor was estimated for each year from 1957 to 1996 by using their time series rates of change for the social rate of return for the non-local highway system (the 1970s to 1980s rate of change was used for years after 1989). Yearly interstate construction costs developed above are used, and a 60 year depreciation schedule is assumed (consistent with the assumptions in Fixed Reproducible Tangible Wealth in the United States, 1925-89 [Washington, DC: United States Department of Commerce, Economics and Statistics Administration, Bureau of Economic Analysis: 1993]). The resulting figure should be considered a general approximation, since additional research is underway to more reliably isolate the benefits of the highway contribution from other potential contributing factors (such as other infrastructure). Moreover, the Nadiri and Mamuneas data on which this estimate is based are aggregate figures for the economy. The production cost impacts vary substantially by industry.

NOTE 2: $1 trillion divided by $329 billion.

NOTE: Based upon the competitiveness of the U.S. economy, it is assumed that virtually all of the lower product costs resulted in consumer benefit through lower consumer prices and higher profits that, in turn, increased business investment and thereby created new jobs.

The same report also found that highways have contributed substantially to national productivity growth. From 1950 to 1989, approximately one-quarter of the nation's productivity increase is attributable to increased investment in the highway system.

NOTE: Nadiri and Mamuneas.

Share of the economy: The interstate highway system is also a direct generator of jobs. As it was being built, it provided thousands of construction and related jobs. It has spawned a large number of new roadside businesses. While the direct impact of the interstates is not known, employment in dining establishments has increased more than seven times the rate of population growth, and employment in lodging establishments has increased at twice the national population growth rate (1958-199).

NOTE: Calculated from data in Statistical Abstract of the United States (multiple annual editions).

NOTE: Calculated from data in National Transportation Statistics 1996.This figure does not include employment in related businesses outside the transport sector, such as road side business.

NOTE: Calculated from National Income and Product Accounts, 1994, Survey of Current Business (Washington, DC: United States Department of Commerce, Economics and Statistics Administration, Bureau of Economic Analysis, January-February 1996).

International Competitiveness and the Interstates: Super-highways got their start with the construction of German autobahns in the 1930s. Indeed, General Dwight D. Eisenhower's fascination with the German system provided major impetus to the vision of the interstates in the United States. Following the Second World War, super-highway construction resumed. When it was completed in the 1950s, Canada's MacDonald-Cartier Freeway from Montreal through Toronto and toward Windsor was the longest super-highway in North America at more than 500 miles. Since then, Canada has built less than 1,500 miles, while the United States has built more than 50,000 miles (including super-highways that are not a part of the interstate highway system). It was not long before the U.S. took unprecedented leadership in developing super-highways through the interstate highway program.

The United States now leads the world by a considerable margin in super-highways. U.S. mileage is nearly 10 times that of the former West Germany, 12 times that of France, 20 times that of Japan and nearly 30 times that of the United Kingdom. In fact, seven states have more at least as much mileage as the entire United Kingdom (California, Florida, Illinois, New York, Pennsylvania and Texas).

NOTE: Calculated from Book of Vital Statistics (London, UK: The Economist Books, 1990).

NOTE: Based upon a ratio of super-highway mileage per 1,000 square miles to population per square mile. Calculated from data in Book of Vital Statistics.

Virtually all major urban areas in the United States are connected to one another by the interstate highway network. This is not so in many developed nations. Super-highway networks contain major gaps or have barely been developed at all. For example:

• Four of the United Kingdom's largest urban areas ---Glasgow, Edinburgh, Aberdeen and Newcastle-on-Tyne --- remain unconnected to the rest of the nation by super-highways.

• Five western European national capitals --- Lisbon, Madrid, Oslo, Stockholm and Helsinki --- are not connected to the European network.
  NOTE: This will remain the case even after completion of the Oresund link across the strait between Denmark and Sweden. A major gap remains between Paris and the closest large urban area in Italy, Turin.

• There is no direct connection between Canada's largest urban area --- Toronto --- and the federal capital of Ottawa despite a distance that is little more than from America's largest urban area (New York) to the federal capital (Washington, DC). The major ports of Vancouver and Halifax, together with Winnipeg, are connected to no other major Canadian urban areas.
  NOTE: Vancouver is, however, connected to the U.S. interstate highway system.

• Gaps remain in the link between Australia's largest urban area, Sydney, its federal capital, Canberra, and its second largest urban area, Melbourne --- a distance similar to the Denver to El Paso Interstate 25 corridor, which is considerably less densely populated. No major urban area in either Australia or New Zealand is connected to any other major urban area by super-highways.

While traffic congestion in urban areas is not unusual in the United States, rural traffic congestion is rare. By contrast, rural traffic delays are far more frequent and serious in Europe.

But the U.S. advantage in super-highways could be challenged by planned improvements. The European Union will spend nearly $100 billion over the next decade to build 9,000 miles of new super-highways and is upgrading an additional 3,000 miles.

NOTE: Commission of the European Communities, Trans-European Networks: Towards a Master Plan for the Road Network (Brussels, Belgium: Commission of the European Communities, Director-General for Transport, December 1992).

The U.S. advantage in super-highways and the significance of the estimated 25 percent highway contribution to productivity is illustrated by the fact that U.S. gross domestic product per capita leads the next most affluent nation, Switzerland, by only 5 percent, Japan by 17 percent and Canada by 20 percent.

NOTE: Only Luxembourg, a highly specialized nation, slightly larger in area than the city of Jacksonville, Florida, with 40 percent fewer people (400,000, compares to Jacksonville's 640,000) has a higher gross domestic product per capita than the United States (based upon purchasing power parities). Purchasing Power Parities and Real Expenditures: EKS Results, Volume I 1993 (Paris, France: Organization for Economic Co-operation and Development, 1995).

A nation's international competitiveness depends on a variety of factors such as its labor force, capital investment, natural resources, and infrastructure. With respect to infrastructure, and in particular, the comprehensive and efficient interstate highway system, the United States holds considerable comparative advantage over its international competitors. The interstate highway system reduces manufacturing and distribution costs in the large domestic market, which, in turn, makes U.S. products more competitive in world markets. This increases employment and, by making the U.S. a lower cost economy, allows its citizens to purchase more with their earnings.

NOTE: For a discussion of comparative advantage in international economics, see Michael E. Porter, The Comparative Advantage of Nations (New York, NY: The Free Press, 1990).

NOTE: U.S. unemployment rates have been considerably below that of European nations for a decade.

The highway system has been very important in maintaining the superiority of U.S. productivity. While estimates for the interstate highway system alone are not available, the efficiency and substantial role of the interstates leads to a reasonable presumption of their important contribution to international competitiveness.

NOTE: Methodology: It is assumed that interstate traffic would be on the non-interstate highway portions of the federal aid-primary (FAP) system if there were no interstate highways. This estimate of lives lost is calculated using the differential in interstate and FAP fatality rates per 100 million passenger miles for the available years (1966 through 1991). Data for unavailable years is estimated based upon a trend analysis. 1995 and 1996 data projected based upon 1994 actual data.

The injury rate for interstate highways is more than 70 percent lower that of the rest of the system. It is estimated that use of the interstates reduced traffic related injuries by 440,000 in 1994 --- as many people as live in Portland, Oregon or Kansas City, Missouri. Over 40 years, the reduction in injuries is estimated at 11.8 million --- equal to the population of New York City, Chicago and Philadelphia combined --- as many people as live in the nation's fifth largest state, Pennsylvania.

NOTE: Methodology: Assumes that interstate traffic would be on the non-interstate highway portions of the federal aid-primary (FAP) system if there were no interstate highways, estimating injuries avoided based upon the differential injury rates for the interstate and FAP systems. Uses available data, and models injury rates for unavailable years based upon trends in fatality rates. 1995 and 1996 data projected based upon 1994 actual data.

• Use of the interstates is estimated to have reduced traffic accidents by more than 400,000 in 1994.

NOTE: Estimated from comparing interstate accident rates with rates for the balance of the National Highway System. Data from 1994 National Highway Statistics.

In urban areas, interstates provide the safest travel.

NOTE: Calculated from data in Highway Statistics 1994 and National Transit Database 1994.

• Urban interstate fatality rates are more than 50 percent lower than that of other roads, while the injury rate is more than 70 percent lower.

• Urban interstate fatality rates are 65 percent lower than urban rail, while injury rates are 50 percent lower.

For each mile of urban interstate highway constructed, more than four lives have been saved and more than 250 injuries have been avoided.

Economic gains from improved safety: There is a significant economic benefit to improved safety. Using National Safety Council estimates of the direct economic cost of traffic accidents, it is estimated that the lower interstate accident rate in 1994 will produce $17.2 billion in direct economic savings.

NOTE: 1994 calculation uses National Safety Council rates as follows: Economic cost: $920,000 per fatality, $34,200 per disabling injury (disabling injuries from the National Safety Council), property and other per accident: $6,600. Quality of life cost: $2,890,000 per fatality, $129,200 per disabling injury (estimated based upon category costs provided, scaled using economic cost categories), $8,600 per accident property and other 40 year estimate based upon National Safety Council rates. Source: Accident Facts: 1995 Edition, (Itasca, IL: National Safety Council, 1995).

From 1957 to 1996, the safety related direct economic losses avoided due to the use of the interstate highway system are estimated at $368 billion (1996$).

NOTE: Based upon National Safety Council costs deflated each year before 1994 in proportion to the size of that year's gross domestic product relative to 1994. Property and other costs are estimated based upon their 1994 relationship to fatality and injury costs.

NOTE: $368 billion divided by $329 billion.

The direct user benefits have been at least equal to the $329 billion user fee investment. But direct user benefits may have been even greater. If it is conservatively assumed that the interstates provide a time savings of 20 to 30 percent, then total time savings for non-commercial interstate use have been between 75 billion and 125 billion hours --- the equivalent of seven to 12 weeks for all 260 million Americans. The value of time saved for non-commercial users was between $45 billion and $77 billion in 1994 and $650 billion and $1.1 trillion over 40 years.

NOTE: The discussion estimates interstate highway system intercity time savings relative to other roadways at 20 percent and urban time savings at up to 60 percent.

NOTE: Based upon Texas Transportation Institute 1992 valuation of time at $10.50 per hour, with the value of time discounted based upon real gross domestic product size for other years as contained in Texas Transportation Institute, Urban Roadway Congestion-1982 to 1992, Volume 1: Annual Report (College Station, TX: Texas A&M University, 1995).

Users have also benefitted from lower vehicles operating costs, through reduced maintenance requirements, improved tire wear, lower oil consumption, and lower depreciation costs, which have more than offset the higher fuel costs attributable to higher speeds. Operating cost savings are estimated at $2 billion in 1996 and $41 billion over 40 years.

NOTE: Operating cost savings for automobiles, light trucks, and vans of 3.14 percent. Calculated from data in Benefits of Interstate Highways (Washington, DC: United States Department of Transportation, Federal Highway Administration, 1983). Actual operating costs from consumer operating expenditures for user operated transportation from the gross domestic product accounts. Interstate operating expenditures estimated based upon annual 1957 to 1996 percentage of total consumer vehicle operation on the interstates.

Other Benefits: The interstate highway system has improved the quality of life for Americans in a number of dimensions that are not readily quantifiable. Nonetheless, each of these benefits has contributed in a material way to maintaining and improving the standard of living.

• Time savings translate into additional time for preferred activities. Travel, especially day to day travel, is generally not an end in itself, it is a means to an end. People travel to get to work, to reach shopping locations, or to keep medical, dental or social appointments, which are primary activities. If people are able to spend less time traveling, they are able to spend more time pursuing preferred activities.

• Expanded mobility allows people to choose from a wider range of options and activities. Faster travel on an interstate can bring more jobs within reach of employees and make it possible for shoppers to take advantage of lower prices or larger selections that may be available at more remote locations.

Additional time and expanded mobility are both products of the interstate highway system. Where mobility improves, opportunity is expanded. Greater employment mobility serves not only the employee, but also the employer and the economy. With a broader geographical range of jobs to choose from, employees are better matched to their employment, improving labor efficiency and productivity. All of this increases economic activity, and translates into a higher quality of life. This is so not only for Americans, but also people in other developed nations, where a close relationship has developed between expanded personal mobility and increasing affluence (1). Personal mobility is both an economic and social asset.

NOTE 1: Especially western European nations..

Democratization of mobility: The interstate highway system has facilitated an unprecedented expansion of mobility and in a democratic manner --- no nation on earth can equal the mobility that is available to the overwhelming majority of Americans. More than 90 percent of the nation's households have access to automobiles, and by extension to the nations' highway system. More than any component of that system, the interstate highway system has expanded the options of people to travel within and between their communities. The interstate highway system provides the crucial express links that make it possible for people to reach virtually any point in their communities for employment or shopping, at whatever time they desire.

Expanded employment freedom: The interstate highway system has made it possible for people to pursue employment across far larger areas than before. People in previously isolated rural areas are now able to use the interstates to reach employment centers. Within urban areas, where interstate highways have reduced travel times up to 60 percent, the interstates make it possible for workers to travel relatively quickly to virtually any location for employment.

Expanded residential freedom: The interstate highway system has played a significant role in producing the American dream of the single family house in the suburbs. As the interstate highway system reduced travel time, people had broader options in residential location. At the same time, lower land prices and increasing affluence made larger dwellings possible, and the size of the average new house has increased by 40 percent over the last quarter century.

NOTE: Statistical Abstract of the United States: 1995 (Washington, DC: United States Department of Commerce, Economics and Statistics Administration, Bureau of the Census, 1995).

Multi-purpose trips: The improved mobility provided by the interstates has supported a significant increase in multi-purpose trips, especially with respect to work trips. People regularly combine child care, shopping, and other trips with work trips, making valuable time available for preferred activities. Indeed, without the interstate highway system, the barriers to mobility would prevent some people from earning a living, and require others to accept less lucrative employment.

Empowerment of the poor: The combination of market priced (lower priced) gasoline and the interstate highway system have truly democratized mobility in the United States. The large majority of households, including households below the poverty line, have automobiles available and are thus able to access a broader range of employment, shopping, and other opportunities. Indeed, the poor in America generally have greater personal mobility by virtue of the automobile and the interstate highway system than many middle income households in developed nations where quality roadways are less extensive.

NOTE: Among developed nations, gasoline prices are closest to market prices in the United States. Most developed nations impose heavy taxes on gasoline, raising prices per gallon to double, triple or more the price of production.

Lower retail prices: America's democratized mobility has lowered retail prices, thus benefitting consumers. As freedom of movement has expanded, people have been able to travel further to shop. At the same time, large discount retailers have been established, placing further competitive pressure on prices. To compete, smaller local retailers have had to become more efficient. One of the most important reasons that people get more for their retail dollar today is that they have more options --- they are able to travel wherever they like for bargains or larger selections that would not be available if they were restricted to shopping opportunities in their own immediate areas. And, because they rely on their own personal transportation, they are able to shop at whatever time they desire. This has encouraged longer store hours, more efficient utilization of retail facilities, and created additional jobs. The interstate highway system has been a major contributor to this advance.

Improved access to health care: The interstate highway system has improved the quality of health care. By making it possible to transport those in need of acute care to hospitals much more quickly and over greater distances, the interstates have reduced mortality. The interstate highway system also improves access to specialists and specialized medical equipment for chronic care patients.

Improved Air Quality: Interstate highways contribute materially to the reduction of air pollution and, thereby, to improved health by permitting more consistent speeds and smoother traffic flows.

NOTE: Committee for the Study of Impacts of Highway Capacity Improvements on Air Quality and Energy Consumption, Transportation Research Board, National Research Council (Washington: National Academy Press, 1995).

NOTE: Steve Nadis and James J. MacKenzie, Car Trouble (Boston, MA: Beacon Press, 1993).

Security: There is considerable concern about personal security in the United States. During the period that the interstate highway system was constructed, violent crime rates increased by more than five times. People tend to feel safe from crime in their automobiles, and the interstate highway system has permitted people, especially women, to confidently travel longer distances at virtually any time of the day.

Leisure activities and vacations: The broadened mobility provided by the interstate highway system has made it possible for people to take longer trips on weekends and during vacations. This, in turn, has generated a significant increase in highway related businesses, such as lodging establishments, restaurants, service stations, etc.

NOTE: "Statement of Lieutenant General Kenneth R. Wykle, United States Army, Deputy Commander in Chief, United States Transportation Command before the House Committee on Transportation and Infrastructure, Surface Transportation Committee, United States House of Representatives, on the U.S. Department of Transportation's Recommended National Highway System" (Washington, DC: March 2, 1995).

The Army also noted the "modal redundancy" of the highway system, which provided rapid and effective movements of a military division when difficulties with a rail line precluded the planned transport by rail.

NOTE: "Statement of Lieutenant General Kenneth R. Wykle."

The 40-year benefits quantified above are estimated at between $2.1 trillion and $2.5 trillion (1996$) --- between 6 and 7.5 times the gross original investment in the interstate highway system. Benefits in 1996 alone are estimated at from $78 billion to $110 billion --- more than the gross state product of Oregon.

But the quantified benefits fall short of the actual benefits that have been produced by the interstate highway system, such as:

• Increased business investment.

• Increased employment opportunities.

• Greater employment mobility.

• Expanded housing opportunities

• Greater economic freedom due to multi-purpose trips

• Greater mobility for low income citizens

• Improved access to health care

• Improved security

• Greater leisure time and broadened vacation options

Each of these benefits do not lend themselves easily to economic analysis, but their impact has clearly been profound. The interstate highway system has improved and enriched the quality of life of Americans.

The percentage of urban interstate lane miles operating at above 80 percent of capacity at peak hour has nearly doubled since 1975.

NOTE: 1994 Highway Statistics.

And, rural interstate congestion, though minimal compared to that of urban areas, continues to grow.

At the same time, the physical structure of the system is in need of attention.

Approximately 60 percent of interstate pavements are rated from fair to poor.

NOTE: Clifford M. Comeau, "Condition and Performance of the Interstate System - After 40 Years," Public Roads (Washington, United States Department of Transportation, Federal Highway Administration, Summer 1996).

Six percent of interstate bridges are structurally deficient.

NOTE: Calculated from 1995 Status of the Nation's Surface Transportation System: Conditions and Performance (Washington, DC: United States Department of Transportation, 1995),

NOTE: Mianus River Bridge on I-95 in Connecticut (1983) and Schoharie Creek Bridge on I-95 in New York (1987).).

The Imperative for Interstate Investment: Expensive as they might appear, improvements are necessary. According to reports prepared for the Federal Highway Administration, the pace of super-highway lane construction in urban areas over one million would have to be increased substantially to stop the growth of traffic congestion. Yet, the annual cost of such would be only $3 billion --- a fraction of the peak annual construction costs incurred during the 1960s and 1970s, and a 2.5 percent increase in the nation's annual surface transportation budget.

NOTE: Lane mile data from Texas Transportation Institute, 1995. Per lane mile cost calculated from data in 1995 Status of the Nation's Surface Transportation System: Conditions and Performance adjusted to reflect 1996 prices.

NOTE: 1994 surface transportation expenditures were approximately $120 billion (1996$), $95 billion for highways and $25 billion for transit.

NOTE: Based upon improved lower fatality and injury rate of the interstate highway system relative to the balance of the federal aid primary system. Average urban interstate assumed to be six lanes. 10 year projection assumes that 1,104 lane miles of urban interstates would be built per year over the period.

NOTE: Conversion from lane miles to roadway assumes an average of six traffic lanes. Lives and injuries avoided based upon comparison of rates between interstates and the federal aid-primary system. Construction costs based on data in 1995 Status of the Nation's Surface Transportation System: Conditions and Performance converted to 1996$.

The increase in traffic congestion takes an additional economic toll in terms of excess fuel consumption and the costs of delay. In 1992, these urban "congestion costs" were $34 billion and were increasing at an annual rate of approximately $2.1 billion.

--- nearly two thirds of the annual cost of required capacity expansion ($3.0 billion, above). Urban super-highway (largely interstate) congestion increases motor vehicle related pollution by consuming more than 14 billion excess gallons of fuel annually --- 58 gallons of fuel per household. This is enough fuel to transport the average household 1,250 miles by automobile (equal to trips from New York to Minneapolis, Seattle to San Diego, Milwaukee to Orlando or Denver to New Orleans).

NOTE: In 1996 dollars. Super-highway congestion costs estimated using relationship of freeway delay hours to total system delay hours. Calculated using data for 50 large urban areas in Urban Roadway Congestion - 1982 to 1992.

A report on 1989 conditions indicated that free traffic flow could be achieved through super-highway (largely interstate) expansions in even the most congested urban areas.

NOTE: 1989 Roadway Congestion Estimate and Trends (College Station, Texas: Texas Transportation Institute, July 1992).

By far the highest cost --- $8 billion --- would be required in Los Angeles --- considerably less than that urban area is spending to build urban rail systems that are unlikely to significantly improve traffic flow.

NOTE: In 1996$, based upon costs calculated from 1995 Status of the Nation's Surface Transportation System: Conditions and Performance.

$1 billion would be required in Washington, D.C. Again, while this is a considerable figure, it represents a relatively small investment compared to other non-highway transportation investments that have failed to reduce the area's traffic congestion.

There has been considerable opposition to expansion of urban interstates, much of it based upon the presumption that expanded interstate capacity is quickly consumed by new traffic. Yet, traffic congestion has declined in two of the nation's fastest growing urban areas (between 1982 and 1992).

NOTE: Urban Roadway Congestion - 1982 to 1992.

In Phoenix, traffic congestion declined by six percent from 1982 to 1992, while population increased by 40 percent (1980-1990).

In Houston, traffic congestion declined by four percent from 1982 to 1992, while population increased by 20 percent (1980-1990).

A major component of the improved traffic conditions in these two urban areas has been a substantial program to build and expand super-highways. By contrast, the average large urban area experienced a 20 percent increase in traffic congestion, while population increased by approximately 10 percent.

Nationally, improvement of interstate highways and other super-highways to support anticipated rates of economic growth would require an annual increase in capital expenditures of approximately $3.5 to $4.5 billion --- $24 billion from 1997 through 2002.

NOTE: Calculated from data for the "Economic Efficiency" scenario in 1995 Status of the Nation's Surface Transportation System: Conditions and Performance.

NOTE: Calculated from data in Statement of Robert A. Sunshine, Deputy Assistant Director for Budget Analysis, Congressional Budget Office, on The Highway Trust Fund, before the Subcommittee on Surface Transportation, Committee on Transportation and Infrastructure, United States House of Representatives, May 16, 1996.

The economic imperative: The nation's continued economic growth depends, in part, on an interstate highway system that grows along with the nation. Population growth will continue. All demographic trends indicate overwhelmingly that people will continue to pursue the "American Dream" of the house in the suburbs and a high degree of personal mobility. But the challenges to U.S. economic growth are substantial. International competitors are becoming stronger, while total compensation per U.S. employee is increasing at lower rates that before. If traffic congestion is permitted to worsen, then American consumers will pay a heavy toll, in higher prices due to higher shipping costs, jobs lost due to foreign competition, reduced employment opportunities, and less leisure time.

America's Future Depends on the Interstates

It has been a momentous 40 years. Interstate highways have contributed to the economic growth and quality of life in America. Indeed, the interstate highway system has been a major factor in making the United States the homogeneous nation that it has become.

The interstate highway system, and other super-highways, will continue to make a positive contribution to the nation's economy and quality of life. This requires that investments be made to preserve and expand the mobility that has helped to make Americans the world's most prosperous people, America the world's premier economic power, and provided an international model for expanding freedom of mobility for virtually everyone. In important dimensions, the future of the nation depends upon the interstate highway system.

The American Highway Users Alliance traces its roots to 1932, when it was chartered by General Motors President Alfred Sloan to "get the farmers out of the mud." The Highway Users (knows as the Highway Users Federation from 1970 to 1995) serves the long-term interests of business and industry in transportation. Many industries are dependent on highways to be successful, including automotive, travel and shipping. Almost 80 percent of all U.S. Expenditures for passenger and freight transportation --- $800 billion annually --- are highway related. Highway passengers spend over $350 billion per year on their travel --- about 12 percent of the nation's GDP. And freight movement over highways counts for 80 percent of all shipping.

The Highway Users works for better, safer highway transportation through public policy analysis, public information and education, and legislative and regulatory advocacy. It believes that good highways are essential to a strong economy and the costs of improving highway transportation should be borne by the users.

Led by President William D. Fay, the Highway Users has over 500 individual and 100 corporate/association members and affiliates in 18 states.

Wendell Cox and Jean Love are public policy consultants with the Wendell Cox Consultancy.

Both have worked on projects in the United States, Canada, Australia, Africa, Europe, and New Zealand. They have recently established an Internet public policy journal, The Public Purpose.

Mr. Cox was appointed to three terms (1977-85) on the Los Angeles County Transportation Commission by Mayor Tom Bradley and has chaired national committees on energy conservation and urban transit planning. He also serves on the steering committee of the bi-ennial International Conference on Competition and Ownership in Surface Passenger Transport. He holds an MBA from Pepperdine University in Los Angeles.

Ms. Love has performed research in a variety of fields, and edited three editions of a comprehensive public policy manual (Legislative Issue Briefs). She organized the Third International Conference on Competition and Ownership in Surface Passenger Transport, held in Toronto in 1993. She earned a Masters degree from Southern Illinois University in Edwardsville.

They are co-authors of many books and papers, including Moving America Competitively, The Livable American City and People, Markets, and Government: A State Legislator's Guide to Economics. Their practice is based in the St. Louis area.