BSM (Blind Spot Monitoring System) and RCTA (Rear Cross Traffic Alert) are two auxiliary technologies that enhance driving safety, but they differ in functions and application scenarios. When the vehicle speed exceeds 15 km/h, if a vehicle in the adjacent lane is detected approaching, it will alert the driver through indicator lights on the rearview mirror and audio-visual warnings to avoid lane-changing risks, which is especially useful for highways or severe weather conditions. It utilizes millimeter-wave radars on both bumpers to detect vehicles or pedestrians moving laterally behind the vehicle and alerts the driver through warnings, effectively reducing collisions caused by limited visibility during reversing, and is commonly employed in complex environments such as parking lots. Although both employ radar technology, BSM focuses on dynamic monitoring during driving, while RCTA specializes in cross-traffic warnings during reversing. Some models such as the Lexus ES come equipped with these two features as standard, while other models can also have them installed through aftermarket upgrades. Note that BSM needs to be temporarily deactivated when towing or installing external accessories to prevent radar interference, whereas RCTA's sensitivity may be affected by confined spaces or unusual terrain.
