The usual view in a mixed economy is that some goods and services are produced privately and some, such as transportation, are produced publicly. Private institutions, such as households and entrepreneurs, produce and conΒ sume goods and services in pursuing their parochial interests, while the pubΒ lic sector attempts to broaden public interests. More precisely, the public sector constructs new transportation systems, improves their capaci ties, and regulates services and prices; and the private sector chooses locations of proΒ duction, modes of transportation, and routes of shipmellt. At the sallie' Lillte'. all forms of transportation influence our lives and cause us concern for Oll r environment, health, and safety. Thus, transportation is intimately woven into the daily life of individuals and organizations in our society. Because of its constant presence, transportation is easy to overlook until it fails in some way. Few would contend that private firms could or should construct an effiΒ cient transportation system in a mixed economic system. Because the entire transportation system must be integrated and coordinated, firms with the power to construct such a system would have considerable monopoly control.