Improving Safety, Mobility and Livability with Better Geometric Design Practices

When it comes to transportation, the United States is compelled to do more with less because of financial and environmental limitations. As a result, U.S. geometric design engineers are squeezing every bit of capacity and safety out of the country’s highway system by using innovative new designs, approaches, practices and policies. This paper describes some of the key U.S. geometric design developments that have emerged over the past five years. This paper also examines the anticipated impacts of these new developments on the transportation community and how they are expected to be documented in various U.S. manuals and guide books. Some advancements occurring in the United States include the formal inclusion of roundabouts and other innovative intersection configurations in national policy. Also, U.S. policies are adapting to fully exercise flexibility for sustainable and environmentally sensitive approaches in design to meet the numerous and diverse needs of U.S. society. New and better tools have been developed for safety and operational analysis, and to improve the decision-making process. This paper also documents where the innovation is taking shape to address the many challenges and concerns in the country’s current transportation environment. Practices such as managed lanes, innovative intersections and higher-order analysis tools for safety and operations are only beginning to make a difference today. Through these future design progressions many of the country’s more complicated challenges will be met and overcome.