How to Use Rearview Mirrors to Judge the Distance of the Following Vehicle?
2 Answers
When judging the distance of the following vehicle, we need to adjust the rearview mirrors. The adjustment is complete when the door handle of the following vehicle is at the middle height of the rearview mirror. When looking at the rearview mirror, it should be divided into "inner side" and "outer side". The half of the mirror closer to you is the "inner side", and the half farther away is the "outer side". If the following vehicle is closer, the visible area of the vehicle in the mirror will be smaller. Conversely, if the following vehicle is farther away, the visible area will be more complete and closer to the inner side of the rearview mirror. If you can only see the hood of the following vehicle through the interior rearview mirror but not the grille, the distance is approximately 3 meters. If the grille is visible, the distance is about 8 meters.
Well, I've found that the key to judging the distance of the following car lies in observing the size change of the vehicle in the rearview mirror, which requires developing some habits. From my daily driving experience: when you've just adjusted the rearview mirror to ensure you can see a small portion of your car's rear window, if the following car appears as tiny as an ant in the mirror, it's generally over 100 meters away; if it starts to occupy half the mirror, it's about 50 meters away; once it nearly fills the entire mirror, it means it's very close, possibly only 5 to 10 meters away, and changing lanes at this point is quite dangerous. I usually like to practice this on highways—when maintaining a constant speed, the gradual increase in the size of the following car helps estimate the closing distance. Combined with the three-second rule, if the following car rapidly grows in size within three seconds, you need to be extra cautious. Don't forget to check the side mirrors to eliminate blind spots and regularly clean the mirrors for clarity—these small details can make your judgment more accurate and ensure safer driving.
