What are the simplest methods to determine a 30 cm margin?

[AaronRose]

There are three commonly used methods to determine if the distance is within 30 cm: 1. Align the front one-third of the car with the right-side line and proceed forward: Generally, the car is divided into three equal parts, and the right one-third of the front is aligned with the right-side line to proceed forward. When first practicing driving, learners often struggle to find this one-third point. Some instructors may advise using the "coach car" text on the hood, aligning the word "coach" with the side line visually. 2. Align the highest point of the wiper with the right-side line and proceed forward: Observe the wiper and align its highest point with the side line to proceed forward. Another less commonly used but easy-to-find reference point is aligning the gap in the wiper with the side line. This method can also be used for stopping within 30 cm in the driving test's roadside parking exercise. 3. Align the right-side reinforcement rib with the side line and proceed forward: Aligning the right-side reinforcement rib with the side line is also a frequently used method.