This report contains the findings of research performed to quantify the safety and operational impacts of design element trade-offs and their associated risks. The report details the research performed and includes specific recommended crash prediction models and Accident Modification Factors (AMFs) for shoulder width and median width on rural four-lane roads.

Contains summaries of the knowledge regarding the effects of 128 road safety measures. This title covers various areas of road safety including: traffic control; vehicle inspection; driver training; publicity campaigns; police enforcement; and, general policy instruments. It also covers topics such as post-accident care, and speed cameras.

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.