The influence of transportation on natural resources

Initially, transportation’s role with respect to natural resources was that it allowed resources to be developed or used. Too much of this occurred, and it has resulted in resources being misused, overused, or exploited as well. Transportation also has made it possible to strip forests of trees, with or without regard for environmental effects on the cleared land or adjacent surface waters. By opening up markets for products, transportation has resulted in lands being converted from a natural state to agriculture. The value of farmland has always been related inversely to the distance to markets. In today’s society, the value of home sites in suburbs is inversely related to the travel times and costs associated with reaching offices and stores in the central city. Patterns of land development in most of the United States were influenced by the land survey requirements enacted in 1785 for what were then the western lands. Townships were laid out in six-mile-square sections; this checkerboard pattern may be seen when flying over the Midwest and prairie states. One section in each township was set aside for education, and this section became the site of a school and often of a small community.

As railroads grew in the mid-19th century, development followed. Studies of population clusters in the Midwest show them located along railroad lines. As major cities expanded, streetcar lines attracted development. Streetcar firms were sometimes bribed by land developers to have new lines serve their undeveloped land, thus increasing its value. Today, roads and freeways influence patterns of suburban growth. They have made it possible for the middle class to flee the central city. Individuals who oppose further growth actively oppose politically any transportation improvements that might open up their area to more development.

Lands often contain mineral and oil resources, and transportation systems have allowed their exploitation. Some of the largest tonnages of products moved in the United States are products of mines, such as iron ore and coal. In ocean shipping, petroleum is the largest single cargo carried. The transportation system itself is the largest consumer of petroleum products; in the United States, highway vehicles consume just over half of all the petroleum. Since petroleum prices escalated in the early 1970s, there has been increased concern with the fuel efficiency of different types of transportation. As petroleum prices decline, interest in fuel efficiency slackens, and automobiles are used more and mass transit less.

Construction of transportation facilities was, in itself, destructive to the environment, but over time the adverse environmental impacts have been tempered somewhat. The best large-scale example is the Trans-Alaska Pipeline, built in the 1970s, whose routing was altered to avoid blocking migration patterns of certain species of wildlife. The construction of sound-deflecting walls near urban freeways and soundproofing structures near airports has helped to control noise. Federal regulations are phasing out the use of noisier aircraft engines.

Disposal of old and abandoned automobiles has caused another land-use problem. Some automobiles are abandoned on streets or in fields; and salvage yards are unsightly. The combination of materials used to construct automobiles often discourages recyclers from paying very much for junked cars to turn into scrap for sale and reuse.

Transportation also has altered water resources. For centuries, wetland areas in ports have been filled in for cargo handling and industrial facilities. Dams and locks have been built to harness major rivers. Flowing streams were used to carry away urban and industrial wastes before sewage treatment plants were constructed. Harbours and navigation channels must be continually dredged to remove accumulated silt. Often this dredged material is polluted, and controversies arise as to where it can be placed so as to minimize damage to the environment. Loading and unloading of dry bulk cargoes generates dust, and port facilities must install extensive systems to collect dust particles. Oil spills are usually contained now before a major disaster occurs, although every year or so there is a major oil spill somewhere in the world.

Air resources are adversely affected by the pollutants generated by the engines that power vehicles. In the United States, the problem is most acute in the Los Angeles area, well-known for its smog. Pollutants come from other sources as well, but transportation is usually acknowledged to be the major villain. Steps are being taken to lower the emissions generated by automobiles and to change driving and commuting patterns to use fewer vehicles. Automobiles are being modified to produce fewer pollutants. There is increased interest in electric automobiles because they generate almost no air pollutants. However, it is possible that the electricity used to recharge their batteries would be produced by a means that generates air pollution. Nonhighway types of transportation also produce air pollutants.