UHF RFID technology is widely used for automatic identification and material-flow monitoring, but read reliability depends on the configuration of the reading system and transport conditions. This study evaluated RFID read reliability during passage of a transport trolley through an identification gate. Six factors were considered: antenna system configuration, identification target, tagged-item arrangement, load configuration, the presence of additional tags, and transmit power. Ninety-six experimental scenarios were tested in three repetitions, giving 288 trials. Complete system-level reads were obtained in 69.1% of trials. Generalized estimating equations (GEE) showed significant effects of antenna system configuration (p = 0.0132), transmit power (p = 0.0292), and load configuration (p = 0.0081). Relative to A1_1, configuration A1_2 increased the odds of a complete read 7.67-fold (95% CI: 1.78–33.08), whereas L2 reduced the odds to OR = 0.24 (95% CI: 0.084–0.691). Higher transmit power increased the odds approximately threefold (OR = 3.06; 95% CI: 1.12–8.35). Repetition agreement was high. The results indicate that RFID-gate performance should be evaluated at the system level because incomplete reads from individual antennas may complement one another.