What is the 30-centimeter technique for oncoming traffic?

[DiMaddox]

The 30-centimeter technique for oncoming traffic mainly involves finding a reference point, shifting to a lower gear in advance, and paying attention to the rear of the vehicle. Here are the specific details: Finding a reference point: When encountering oncoming traffic, the right side of the vehicle should ideally be 30 centimeters away from the solid line on the right. The method is similar to pulling over to the side of the road. For example, take a prominent point on the windshield wiper as a reference. When this point aligns with the solid line on the right, the distance between the vehicle and the line is approximately 30 centimeters. Additionally, any noticeable point on the vehicle can be used as a reference. Since each driver's height and viewing angle differ, the reference point may vary. Shifting to a lower gear in advance: When performing the oncoming traffic maneuver, immediately apply the brakes to reduce speed and shift to a lower gear beforehand. During oncoming traffic, attention is primarily focused on observing distance and adjusting direction. Most learners should avoid simultaneously steering and shifting gears during this maneuver. Watching the rear of the vehicle: This means paying attention to the rear of the oncoming vehicle to avoid unexpected obstacles. When the oncoming traffic is nearly completed and the rear of the oncoming vehicle is not yet visible in the rearview mirror, be cautious when turning, as there is a high risk of a collision.

[DelAngelina]

When it comes to the technique of maintaining a 30cm distance during oncoming traffic, as someone who has driven many long-distance trips, I believe the key lies in identifying reference points and driving slowly. First, adjust your sitting position so that your body is directly facing the steering wheel and your line of sight remains parallel—this ensures accurate distance judgment. The edge of the hood is a great helper—if you see the roadside line aligned with the outer one-third of the hood, that’s roughly 30cm. Keep your speed between 10-20 km/h, crawling like a snail, and avoid sudden acceleration. On narrow roads, it’s best to observe oncoming vehicles in advance and proactively slow down to yield. Don’t forget to make slight steering adjustments; turning the wheel slightly to the right can create enough space. Practice on a quiet side road using water bottles as markers a few times, and muscle memory will naturally develop. Safety is paramount—if you’re unsure, it’s better to stop and let the other vehicle pass first to avoid costly repairs and delays from scratches.

[LeEliza]

From my early days as a novice to now, I've realized that mastering the art of passing other vehicles is all about practice makes perfect. At first, I was always afraid of getting too close, but later I discovered that the position of the car's front is crucial: if the corner of the right windshield aligns with the roadside line, it's roughly half a meter away; for 30 centimeters, the roadside line should align with the middle plastic piece of your wiper. Slowing down gives you more reaction time, especially on slippery rainy days when you need to crawl at a snail's pace with your foot hovering over the brake, ready to stop at any moment. On narrow village roads, I always lean out to check the left rearview mirror to ensure the rear wheels won't scrape against the ditch. Keep the rear of the car from leaning too far left, maintaining a straight body for safety. Every time I pass through those tight alleys, I treat it as a practice opportunity. Over time, you'll be able to maneuver by feel without even needing reference points.

[DamianAnn]

Maintaining 30 cm distance mainly relies on two points: slight body adjustment and visual alignment. First, steer the front of the car slightly to the right, keeping about one car door's width from the curb. Watch the lower corner of the right rearview mirror—when it aligns with the roadside white line, you've roughly achieved 30 cm. Keep speed under 10 km/h and make steering adjustments within half a turn. If encountering oncoming traffic, slow down and yield right of way—safety first. Practice parking against walls a few times to quickly develop spatial awareness.

[MacClara]

When teaching my child to drive, I always emphasize that 30 centimeters is the safety baseline. Beginners tend to get nervous and drive too close to the roadside, so they need to be taught to watch the position of the right front wheel—it's correct when it almost grazes the lane line. In the rearview mirror, the edge of the car body should not exceed the width of the roadside line. Slow down in advance when meeting another car, and stop completely if the distance isn't enough. I recommend practicing straight-line driving in an empty parking lot with two rows of cones, then moving to narrow roads for real-world practice. Don't turn the steering wheel all the way; gently guiding it is enough to slowly adjust the position.

[OLandon]

From a physical perspective, the 30-centimeter distance depends on vehicle length and sightline height. For sedans with lower seating positions, aligning the right windshield wiper pivot with the curb serves as the reference point; for taller SUVs, observe the lower edge of the side mirror. When approaching oncoming traffic, slow down first and slightly steer right to create an angled approach—this ensures proper clearance when straightening. During rainy conditions or poor nighttime visibility, rolling down windows to check tire positioning improves accuracy. With practice developing spatial memory, conscious measurement becomes unnecessary.