The authors present a methodology useful for developing forecast of U.S. Traffic Safety trends. Although many researchers have described traffic accidents as being difficult: to forecast due to the thousands of factors potentially contributing to an accident, it is possible to develop mathematical equations that are useful for estimating traffic accident trends. These equations can be used at the macro level-aggregate numbers of accidents or at the Micro level for safety program evaluation, assessment of regulatory impacts as to help develop national traffic safety plans and policies. Results of alternative model specifications and tests of the equations for developing accident projections are presented. The authors also recommend that the use of the methodology be considered for accident analysis and trend decomposition as well as for developing a more comprehensive traffic safety information system.