The purpose of this project is to study the economic and social impact of a section of the Federal Clean Air Act Amendments of 1990 that requires all employers with 100 or more employees in metropolitan areas with severe ozone noncompliance to implement plans to increase the average vehicle occupancy of commuting employees. The metropolitan area to be studied will be Baltimore, with five objectives to be met: document the economic effects of the regulation on business; identify the economic and social effects of the regulations on employees and on employer/employee relationships; document the effectiveness of business efforts to change employee commuting behavior; identify how various information and change strategies can affect cost of compliance and the effectiveness of change strategies; and provide information back to the system rapidly enough to result in corrective action to achieve the target more effectively. The study requires a quasi-experimental model. While businesses are required to develop plans for complying with the regulations, the change processes which those plans will use can vary greatly, and these variations can be studied. Moreover, the way in which businesses obtain the information necessary to understand the regulations, develop plans, and implement change will also vary and can be studied. This project focuses on the socio-behavioral side of commuting and seeks to apply change models, mid-range organizational theories, and other empirical findings to understand, predict, and change actual commuting behavior.