Transit Rail Inspection Practices Act of 2018 or the TRIP Act (Sec. 2) This bill directs the Department of Transportation (DOT) to develop and disseminate to state safety oversight agencies (SSOAs) the process and methodology that it will use to monitor the effectiveness of the enforcement authorities and practices of the SSOAs. A state safety oversight program shall provide the SSOA with the authority and capability to enter the facilities of each rail fixed guideway public transportation system that the SSOA oversees to inspect infrastructure, equipment, records, personnel, and data. A SSOA shall establish policies and procedures: (1) regarding the access of the SSOA to conduct inspections of the rail fixed guideway public transportation system, and (2) for collecting data from a rail fixed guideway public transportation agency. A rail fixed guideway public transportation agency shall provide the applicable SSOA with the data that the rail fixed guideway public transportation agency collects when identifying and evaluating safety risks. DOT shall issue a special directive to each SSOA on the development and implementation of risk-based inspection programs. (Sec. 3) The bill increases the apportionment percentage for state safety oversight program grants.