TRB’s Commercial Truck and Bus Safety Synthesis Program (CTBSSP) Research Results Digest 2: A Status Report describes the progress and status of the Commercial Truck and Bus Safety Synthesis Program (CTBSSP). CTBSSP is a cooperative research program sponsored by the Federal Motor Carrier Safety Administration (FMCSA) and administered by the Transportation Research Board. The program was authorized in late 2001 and began in 2002 in support of the FMCSA’s safety research programs.