As part of FTA’s effort to promote continuous safety improvement in the public transit industry, these Guidelines for Performing Transit Bus Accident Investigations were developed to provide bus transit agencies leading transit industry practices for performing investigations. The supporting Transit Bus Accident Investigations—Background Research provides a comprehensive examination of each SMS element to broaden the reader’s understanding of how each component complements the others. The recommended practices described in this document and emphasized through the background research are not intended to be prescriptive in nature. Each public transit agency is responsible for tailoring its event investigation processes to its unique operating environment, the complexity of the operation, and the transit modes provided. These locally-developed processes should correspond to a transit agency’s existing Standard Operating Procedures (SOPs) or emergency plan.