“One-Way-Out”: Contraflow Freeway Operation for Hurricane Evacuation

Abstract

Over the past 20 years the coastal population of the southeastern United States that is vulnerable to hurricanes has increased significantly. Much of the recent planning and construction of infrastructure in these regions has taken place during a two-decade lull in hurricane activity. It is now apparent that these areas are not all suitably equipped to deal with the threat of severe hurricanes. As a result, a significant percentage of the coastal population is forced to evacuate under the threat of major hurricanes. This has been demonstrated recently during Hurricane Floyd in 1999 and during Hurricane Georges in 1998. One method suggested to meet the need to evacuate large numbers of people in a rapid and efficient manner is to contraflow segments of interstate freeway. Under contraflow operation, some or all inbound lanes of a freeway are used for outbound evacuation. While the concept is simple, implementation is complex. This paper discusses the advantages and disadvantages of contraflow operation on freeways during hurricane evacuations, including the capacity benefits, critical planning, design, and operational issues, and current contraflow operation plans from threatened states. The paper also provides a list of recommendations and needs that should be considered in the planning and implementation of contraflow evacuations.