This guide is intended for managers of departments of transportation (DOT) charged with leading and managing agency programs impacting the project development process and safety programs. This guide is based on lessons learned from early adopters of the Highway Safety Manual (HSM), many of whom are participating in the AASHTO’s Lead State Initiative. It outlines what the HSM is (and is not), how it relates to other core technical documents and policies, and the potential benefits of its use. These benefits can be broadly understood as a means to improve the safety performance of their highway system. In this context the improvement of safety is defined as a reduction in fatalities and injuries. The guide is written in three sections – Introduction to the HSM, HSM Implementation Considerations, and HSM Implementation Opportunities in Program Development and Project Delivery.