Explore the Art and Science of Geometric DesignThe Geometric Design of Roads Handbook covers the design of the visible elements of the road-its horizontal and vertical alignments, the cross-section, intersections, and interchanges. Good practice allows the smooth and safe flow of traffic as well as easy maintenance. Geometric design is covered in d

Context-sensitive solutions (CSS) reflect the need to consider highway projects as more than just transportation facilities. Depending on how highway projects are integrated into the community, they can have far-reaching impacts beyond their traffic or transportation function. CSS is a comprehensive process that brings stakeholders together in a positive, proactive environment to develop projects that not only meet transportation needs, but also improve or enhance the community. Achieving a flexible, context-sensitive design solution requires designers to fully understand the reasons behind the processes, design values, and design procedures that are used. This AASHTO Guide shows highway designers how to think flexibly, how to recognize the many choices and options they have, and how to arrive at the best solution for the particular situation or context. It also strives to emphasize that flexible design does not necessarily entail a fundamentally new design process, but that it can be integrated into the existing transportation culture. This publication represents a major step toward institutionalizing CSS into state transportation departments and other agencies charged with transportation project development.

TRB's National Cooperative Highway Research Program (NCHRP) Report 659: Guide for the Geometric Design of Driveways explores guidelines related to the geometric design of driveways. The report includes driveway-related terms and definitions, an examination of basic geometric controls, a summary of access spacing principles, and detailed discussions of various geometric design elements. Material related to and supporting the contents of NCHRP Report 659, including an extensive review of literature, has been published as NCHRP Web-Only Document 151: Geometric Design of Driveways.