This report is geared towards motor carriers and documents the Carrier Safety Measurement System (CSMS) methodology developed to support the Compliance, Safety, Accountability (CSA)program for the Federal Motor Carrier Safety Administration (FMCSA).The SMS has two components. One component measures the safety of individual motor carriers, CSMS, which is documented in this report. CSMS results are fully available to the assessed carriers. A subset of the results is publicly available. The other component is the Driver Safety Measurement System (DSMS), which measures the safety of individual commercial motor vehicle (CMV) drivers. The methodology for DSMS can be found in separate document at (http: //csa.fmcsa.dot.gov/Documents/Driver_SMSMethodology.pdf).DSMS results are strictly used as an investigative tool and are onlyavailable to law enforcement (i.e., DSMS results are not available to the public, motor carriers, or drivers