Geometric Design Guidelines for Suburban High-Speed Curb and Gutter Roadways (1347-1F)

The objective of this study was the development of geometric design guidelines for suburban, high-speed curb and gutter roadways. Design elements that were addressed included design speed, alignment, cross section, drainage, driveways, and sight distance. Safety studies, operational studies and clear zone studies were conducted. Field data collection sites for the studies were selected from various areas throughout the state of Texas. The safety studies analyzed the safety effects of high-speed curb and gutter roadway sections through accident rates, accident severities, and accident characteristic frequencies. The operational studies included a study concerning shoulder requirements and two-way left-turn lane (TWLTL) requirements. The clear zone study was conducted to determine the most appropriate and cost-beneficial clear zone width requirements for suburban high-speed curb and gutter sections.|The resultant guidelines were based on the input from a panel of experts and the results of several safety, operational, and computer simulation studies. They were prepared in a format such that they can be inserted into the current edition of TxDOT's Design Manual. The geometric design criteria for suburban highways were prepared in both English and metric units. Adoption of these guidelines should result in a consistent, safe and defensible set of geometric design guidelines for suburban high-speed curb and gutter roadways.