Highway safety is an ongoing concern to the Texas Department of Transportation (TxDOT). As part of its proactive commitment to improving highway safety, TxDOT is moving toward including quantitative safety analyses earlier in the project development process. The objectives of this research project are: (1) the development of safety design guidelines and evaluation tools to be used by TxDOT designers, and (2) the production of a plan for the incorporation of these guidelines and tools in the planning and design stages of the project development process. This document describes a procedure for using accident modification factors in the highway design process. Application of the procedure entails the use of several factors, where each factor addresses one specific design element (such as lane width, shoulder width, curve radius, etc.). Collectively, the factors can be used to estimate the effect of a change in one or more design elements. The procedure can be used to evaluate the safety benefits associated with alternative geometric designs.