Effects of varying functional classification on cost of roadways

Weakened purchasing power and dwindling funds are causing transportation agencies to rethink their engineering practices in order to achieve more cost-effective designs. Increasing public awareness of the impact of highway construction on the surrounding environment has also resulted in pressure on transportation agencies to minimize impacts by incorporating context sensitive solutions in their designs. Major design criteria, such as design speed and design traffic volume, ultimately determine how expensive a project will be and the level of environmental impacts that it will have. Selection of design criteria, however, begins with the determination of the functional classification of the roadway. The purpose of this technical note is to determine the costs and impacts of several typical roadways with different functional classifications, using typical design criteria for each functional classification. This work is not presented as fundamental research, but is intended to provide decision makers with an estimated range of costs and impacts associated with different functional classifications in different types of terrain, for use in making early policy level decisions.