The highway transportation system may be viewed as a commons, that is, property that is owned by everyone and open to use by everyone. However, a commons has certain characteristics that lead to its exploitation or even demise. The motor carrier industry is used to illustrate the dilemma posed by the commons and how existing systems of deterrents and incentives fail to promote safety. Recommendations are made for modifications in motor carrier safety regulations to take into account the commons characteristics of the highway transportation system. This paper is an attempt to relate risk policy in highway safety to a framework developed out of biological theory and thinking. The paper begins with Garrett Hardin's description of the tragedy of the commons and shows how highway safety issues, specifically, those in heavy truck transportation, may be fitted into that context. Next it examines the implications of this frame of reference for risk policy, showing how current policies may serve to aggravate existing problems rather than having an ameliorative effect. Finally, the paper makes recommendations for modifying our policies so as to come closer to achieving the desired goals.
THE DILEMMA OF THE COMMONS
Hardin's classic essay (1968) describes the problems inherent to a commons, that is, property that is owned by everyone and open to use by everyone. (The famous Boston Commons is an historical example.) Hardin's illustration is a pasture that is owned by the community and on which all members of the community graze their livestock. For every pasture, regardless of its size, there is a limit to the amount of grazing that can be sustained. Beyond that limit, the pasture can no longer regenerate itself and at that point the welfare of the entire community may be endangered.
The dilemma of the commons was described even earlier by Lloyd as follows:
Each of ten people own one 1000 pound bull and all ten bulls graze upon a common pasture that is capable of sustaining them all. If an additional bull is introduced, the weight of each bull would be decreased to 900 pounds; that is, with the introduction of an additional bull, the pasture could support only 9900 pounds of cattle, rather than 10,000. Any individual who introduces an additional bull has increased his wealth by 800 pounds because he now has two 900 pound bulls rather than one 1000 pound bull. The total wealth has been reduced by 100 pounds, as has the wealth of each of the other individuals. (Lloyd, 1833/1977, cited in Edney, 1980.