This report presents the results of its assessment of transit service integration practices in the United States. Initially, a review of the literature was performed that identified the various types of service integration policies that have been and are being implemented including infrastructure, schedule, information, fare payment and special events/emergency service integration. The review also revealed how the introduction of service integration practices is part of overall changes in transit properties' way of conducting business. The research then made use of a twostage survey of transit agencies which have implemented specific practices. The initial survey cast a wide net to identify service integration practices across the country by approximately 100 agencies. The subsequent survey targeted specific examples of each type of practice and examined the objectives of the practices, the agency responsible for promoting integration, the effectiveness of the practices, the measures of effectiveness, the barriers overcome and the lessons learned. Transit agencies that have implemented integration practices have been able to overcome barriers to coordination and integration and have made a number of trailblazing efforts. While there has been little formal evaluation of these practices by transit agencies, the predominant view is that transit integration supports the overall goals of the transit agency and provides substantial benefits to the customers. Data to support impact evaluation is limited; however several case studies were also conducted quantitatively and qualitatively as part of this project. Lessons learned and guiding principles are also provided.