The objectives of this project were to evaluate data related to user costs on various highway facilities under different levels of service, volumes, and other conditions, and to develop a methodology for relating these variables to user costs and to air pollution and noise effects. The research was to include sensitivity analyses to identify the highway design and situation variables that have major impacts on output variables and therefore should be included in results presented to highway decision makers. The research team from Stanford Research Institute compiled and updated motor vehicle running cost data for use in calculating relative road user costs at different levels of highway service as affected by details of geometric design and traffic performance. By use of appendix A of the highway capacity manual, relationships were derived for peak-hour volume per lane as a function of AADT per lane pair. Queuing was analyzed based on the shock wave method for uninterrupted flow and the deterministic method for interrupted flow. A methodology for estimating vehicle emissions was developed based on prototypical vehicle results and projected trends in pollution control standards.