How to Determine the Distance from the Following Vehicle Using the Rearview Mirror?

[Kaylee]

First, adjust the rearview mirror properly, with the standard being able to see the door handle, and the height of the door handle should be at the middle height of the rearview mirror. Remember the principle: closer objects appear larger, while distant objects appear smaller. In summary, the larger the following vehicle appears in the rearview mirror, the closer it is to your vehicle.

[Alexander]

I've been driving for many years and judging the distance of the car behind me relies entirely on the experience accumulated from using the rearview mirror. The basic method is to observe the size ratio of the following car in the mirror: if the entire front of the car, including the bumper and lights, is clearly visible, the distance is usually more than 20 meters away, which is still relatively safe; if the car only occupies half of the mirror or you can only see part of the front, then it's within 10 meters, and you need to pay attention immediately. I often practice this on the highway, such as when a car behind rapidly approaches, it quickly fills the mirror, reminding me to increase the distance. The size of my own car also affects the judgment—when I drive an SUV, the mirror's perspective is wider, making sedans appear closer. Before changing lanes, I use this technique combined with checking the side mirrors to prevent rear-end collisions, ensuring safety and stability.

[MacAxel]

From a safety perspective, judging distance using rearview mirrors should never be taken lightly. I prefer observing the position of the following vehicle relative to the mirror: if it's at the edge of the mirror and appears as a small speck, the distance is considerable. However, if the tires are clearly visible or the vehicle occupies the center of the mirror, it's too close—likely within 20 meters. I exercise extra caution during rain or at night when visibility is poor and misjudgment is easier. While driving, I remind myself not to rely solely on mirrors—glancing at blind spots every few seconds is more reliable. Early in my driving days, I once backed into another car while parking due to misjudging distance, so I recommend testing reference points before each drive, like observing a marker on an empty road. Safety comes first; gradually developing these habits helps avoid risks.

[VonAthena]

Let me briefly explain my method: Observing the details of the following vehicle in the rearview mirror is key. If you can clearly see the entire license plate or hood of the car behind, the distance is usually over 30 meters; when both the windshield and front end of the following vehicle are visible in the mirror, the distance shrinks to within 15 meters. Having driven for ten years, I've developed this habit for quick judgment—especially in urban traffic jams where frequent lane changes require adjusting speed based on mirror positioning. Remember to set the mirror angle correctly—not too high to block the rear window. This technique proves most practical when reversing in parking lots, supplemented by sound or radar assistance. Developing this intuitive reaction ensures confident driving.