How to Determine Overtaking Distance by Observing the Rearview Mirror?
2 Answers
To determine the overtaking distance by observing the rearview mirror, follow these steps: 1. Divide the rearview mirror into inner and outer sections. The closer the following vehicle is, the smaller the visible area of the vehicle will appear, and it will also be positioned more towards the outer side of the mirror, typically at a distance of about 25 meters. 2. The farther the following vehicle is, the more complete its visible area will be, and it will appear closer to the inner side of the mirror. Whether it's the left or right rearview mirror, consistently define the half of the mirror closer to you as the "inner side" and the half farther from you as the "outer side." This method applies to judging vehicles approaching from either the left or right rear.
Having driven for decades, I rely solely on visual references from rearview mirrors to judge overtaking distances. When you intend to overtake on the highway, first observe the size of the vehicle behind you through the driver's side rearview mirror. If the car appears very small in the mirror, like a dot, the distance is typically over 100 meters, which is safe for overtaking. If it appears large, occupying more than half of the mirror's surface, the distance is too close—less than 50 meters—and you should wait for a better opportunity. I always make it a habit to confirm for at least two seconds before overtaking, checking blind spots with the side mirrors to avoid sudden rear-end collisions. Remember, visibility worsens in rain or fog, making distance judgment harder, so always leave extra margin. Additionally, the faster your speed, the quicker the distance closes—for example, at 120 km/h, changes in the mirror require more immediate attention. I recommend that beginners practice this technique every time they drive to develop the habit.
