How to Determine the 30 cm Distance When Reversing into a Parking Space?
3 Answers
When the right one-third of the vehicle's hood aligns with the sideline, you can determine the 30 cm position. If the learner fails to judge the point accurately on the first attempt, multiple adjustments can be made to ensure the vehicle does not cross the line. When the highest point of the vehicle's wiper aligns with the right sideline, the 30 cm position is determined. During the approach, maintaining a slow speed provides opportunities for adjustments. When observing from the right rearview mirror and noticing that the front door handle aligns with the sideline, the 30 cm position is determined. The steering wheel should be turned in small increments multiple times, avoiding excessive steering movements.
When I first started learning to reverse into a parking space, I always struggled with judging the 30 cm point. My instructor taught me to make more use of the rearview mirrors: when the car body is completely parallel to the parking line, observe the distance between the car body and the edge in the mirror. The ideal state is about one and a half palm widths (around 15 cm), because small errors are allowed in actual parking. Don’t just look at one mirror; check both sides to ensure even symmetry. During practice, find an open area with marked lines to test, and measure and summarize your experience each time you reverse in. Another trick is to use the reflection on the ground or the position of the wheel edges to assist in judgment. Safety first—if you’re unsure, stop and get out to take a look; don’t rush to finish. Remembering this point can effectively avoid scraping the wall and make passing the test easier. With practice, muscle memory will help you master it.
Having taught driving test students for many years, I believe judging 30 centimeters relies on reference points combined with feel. During the parking process, focus on the position of the parking spot corner in the rearview mirror—when it reaches the height of the lower edge of the rear wheel, it indicates the distance is approximately 30 centimeters. Turn the steering wheel slowly and steadily, avoid sudden movements. In actual driving, keeping the error within 10 centimeters is safe, such as ensuring the gap between the tire and the curb or marking line is within a fist's width. During practice, having a partner stand outside the car to guide you is more intuitive. Also, check if the tire pressure is balanced, as low tire pressure can affect the car's posture. This skill not only helps pass the test but also makes daily parking smoother.
