How to Determine the Distance to the Rear Vehicle Using Rearview Mirrors?

[VonCooper]

The methods to determine the distance to the rear vehicle using rearview mirrors are: 1. If the rear vehicle is located on the outer side of the rearview mirror, it indicates a closer distance; if it is on the inner side, it indicates a farther distance; 2. The larger the rear vehicle appears in the rearview mirror, the closer it is; the smaller it appears, the farther it is; 3. When the internal rearview mirror shows the hood of the rear vehicle but not the grille, the distance is approximately 3 meters; 4. When the internal rearview mirror shows the grille of the rear vehicle, the distance is approximately 8 meters; 5. When the internal rearview mirror fully shows the wheels of the rear vehicle, the distance is more than 20 meters.

[Clarisse]

When driving on highways or urban roads, I primarily rely on visual reference points in the rearview mirror to judge the distance of the vehicle behind. If the following vehicle appears very small, occupying only a small portion of the mirror with visible empty road space around it, this indicates it is at a safe distance, roughly over 200 meters. If the vehicle grows larger, filling more than half of the mirror, it means the distance has narrowed to within 100 meters, and heightened caution is necessary. Another technique is observing whether the lower part of the vehicle is clearly visible; if it appears blurry or has blind spots, it signifies the vehicle is very close. Having driven for many years, I often remind myself to use the side mirrors in combination to avoid focusing solely on the rear while neglecting blind spots on the sides. Beginners tend to rely solely on instinct, but with practice, this skill becomes second nature. Weather conditions also affect judgment, such as blurred glass during rain or glaring lights at night, making it more important to reduce speed. Maintaining this habit consistently helps prevent rear-end collisions and facilitates lane-changing maneuvers.

[SanOlive]

Safe driving is my top priority, and accurately judging the distance of the following vehicle is crucial for road safety. By observing through the rearview mirror, if the following vehicle appears tiny, like a small dot, it usually indicates a buffer zone of 200-300 meters, giving you ample time to react calmly. If the vehicle grows larger and occupies the center of the mirror, it means it's closing in, now within 100 meters—avoid sudden braking to prevent a collision. I always educate passengers in the car to adjust the rearview mirror angle properly, ensuring a wide field of view that captures the full road scene outside the window. Additionally, combining speed perception improves accuracy, as distances change faster at higher speeds. Cultivating this habit in daily driving can significantly reduce accident rates and promote a mindset of courteous driving.

[DelFernando]

When I first learned to drive, the most useful tool for judging the distance of the car behind me was the rearview mirror. Simply put, observing the size of the following car in the mirror gave me clues—smaller meant farther away, while larger indicated it was close. Specifically, if the car occupied only a small portion of the mirror and the road edges were still visible, it was safe. However, if the car covered most of the mirror, caution was needed. Initially, I worried about getting it wrong, but after repeated practice with my instructor, I can now estimate the distance with just a glance. This skill has boosted my confidence when driving in congested city traffic.