Why do we use a rear view mirror in vehicles?

The car rearview mirror is one of the core components for safe driving of vehicles. Its design includes interior rearview mirrors (flat mirrors, used to observe the area directly behind and inside the vehicle) and exterior rearview mirrors (convex mirrors, which expand the side field of vision). Some commercial vehicles are also equipped with lower rearview mirrors to cover the blind spot in the front lower area. Rearview mirrors can significantly reduce safety hazards during lane changes, overtaking, and reversing. For example, assessing the distance to the vehicle behind using the interior rearview mirror can help prevent rear-end collisions, while the exterior rearview mirror enables monitoring of side traffic to avoid side-swipe accidents. Specific guidelines must be followed when adjusting: the interior rearview mirror should centre the horizon without reflecting the driver's own image; the left exterior rearview mirror should maintain a 1/4 vehicle body proportion; the right one should increase the ground proportion to 2/3 to accommodate roadside parking needs. From a regulatory standpoint, the mandatory installation of rearview mirrors underscores their irreplaceable role in lane management and blind spot mitigation. Drivers should cultivate the habit of regular observation and supplement it with head checks to fully eliminate visual blind spots.