Citing the growth in volume of pedestrians and bicyclists on the nation's roads "along with corresponding increases in collisions and fatalities," AASHTO's Standing Committee on Highways voted to develop "robustly researched guidance" to roadway engineers on how best to incorporate varied travel modes when designing roads and streets.
The committee approved a resolution May 25 at the AASHTO spring meeting in Des Moines, Iowa, that said its Subcommittee on Design will develop the guidance, and that it will incorporate peer-reviewed design flexibility standards for the next edition of the association's widely used "Green Book."
The committee resolution called the Green Book "the preeminent design guidance for streets and roadways in the United States."
"We have seen consistent growth in walking and biking throughout the country, and we also have seen an increase in crashes and fatalities involving them," said Kirk Steudle, Standing Committee on Highways chair and director of the Michigan Department of Transportation. "Our state agencies need robustly researched guidance on how to best incorporate all modes of travel when designing safe and efficient roadways that serve all users."
The committee is made up of top design engineers from various state departments of transportation, and brings together best-practices expertise from around the nation to review new methods or technologies for various publications including the Green Book.
AASHTO said that publication, formally named "A Policy on Geometric Design of Highways and Streets," consists of research-based, peer-developed guidance that serves as the basis for design of roads on the National Highway System, as well as many state and local roads. It is used by state DOTs, local agencies and companies that contract to design and build roads.
The committee is in the early stages of one of its periodic updates to the Green Book, and as a result of the committee's resolution that update will focus more guidance on designs that meet the growing demand for bike and pedestrian lanes and how to protect them from collisions with motor vehicle traffic.
In the resolution, the committee noted there is a lack of the type of quality design guidance in the marketplace that this Green Book update can bring. "Other publications provide examples for multimodal street design, but there does not exist research-based, peer-reviewed design guidance that fully address the technical design-related aspects of these issues," it said.
Bud Wright, AASHTO's executive director, said that "multimodal design philosophies have been described using a variety of names, including context-sensitive solutions, practical design and complete streets. Regardless of the name, the ultimate goal is always to design a safe transportation system that supports a greater quality of life and robust economy."