PHYSICAL CHARACTERISTICS AND COST-EFFECTIVENESS OF ARTERIAL FLYOVERS

One bottleneck created by a congested signalized intersection can significantly reduce the through-traffic capacity of an arterial. The flyover, a grade-separated structure that diverts arterial through traffic over the at-grade intersection, can overcome such limitation in a cost-effective manner. Usually, this result can be accomplished within the existing right-of-way of 100 ft or wider even after the at-grade cross section has been fully developed. Benefits are related to the total amount of traffic using the at-grade intersection. Costs are the result of method and type of construction, traffic delay and diversion during construction, and impacts to adjacent properties. The benefit-to-cost ratio of nine potential flyovers in Texas was estimated to range between 1.3 and 12.5.