The National Transit Database (NTD) includes comprehensive data on transit organization characteristics, vehicle fleet characteristics, revenues and subsidies, operating and maintenance costs, vehicle fleet reliability and inventory, services consumed and supplied, and safety and security. Some of these data have been used extensively to derive values for transit performance measures and have become the sole source of standardized and comprehensive data for use by all constituencies of the U.S. transit industry. An important application of NTD data has been in trend analysis, which requires multiple years of data. However, accessing NTD data, especially for multiple years, has not been an easy process. One reason is because the data were collected and distributed annually in separate files. This paper introduces a webbased system that integrates over 20 years of NTD data and provides user-friendly tools designed to facilitate the access and analysis of transit performance data.