How many centimeters is the maximum allowable deviation for straight-line driving?

[FrankLee]

Straight-line driving should not deviate more than 30 centimeters to either side. Straight-line driving refers to novice drivers starting the vehicle, gradually accelerating by shifting gears from the lowest to the highest gear to achieve high speed. The assessment requirements for straight-line driving are: 1. Requirement one: The driver must start smoothly and maintain a basic sequence of driving operations. 2. Requirement two: The driver should correctly handle the steering wheel (primarily using the left hand) and use the steering wheel's free play to adjust the driving direction. 3. Requirement three: The driver must master the timing and methods of gear shifting, skillfully switching between high and low gears at various speeds (sequential upshifting, sequential downshifting, or skip downshifting). 4. Requirement four: The driver should be able to timely and effectively apply the brakes (predictive braking for deceleration). 5. Requirement five: The driver should basically master the methods for fixed-point parking and intersection U-turns.

[LaylaMarie]

I've been driving for nearly twenty years. When driving straight, the car must not deviate too much, generally within 10 to 15 centimeters is the safest, otherwise it's easy to cross the line and cause an accident or a fine. The average lane width is about 2.5 meters, and the car is 1.8 meters wide. Excessive deviation in the middle is like that time when I was young and driving on the highway. After deviating more than 20 centimeters, the car skidded and nearly hit the guardrail. Now I always use distant streetlights as reference points to easily adjust the steering wheel. Don’t underestimate this slight deviation; uneven tire pressure or suspension issues can amplify it. I recommend everyone develop a habit of checking, and beginners should practice their feel in open areas first. Be extra careful in rain or snow; keeping the deviation under control can greatly reduce the risk of skidding.

[AdelineFitz]

As someone obsessed with automotive electronic systems, I believe the straight-line deviation should not exceed 30 centimeters, otherwise the lane departure warning system will go crazy. That thing uses cameras to scan lane markings, and when the deviation exceeds 30 centimeters, it reminds you to steady the steering wheel. For daily driving, it's best to keep it under 20 centimeters to save fuel and reduce wear. My car is equipped with active steering assist, which automatically makes minor adjustments to the position. Additionally, the onboard system can now display real-time deviation data, and you can track historical records via an app, making it easier to maintain wheel balance and ensure smarter, safer long-distance driving. On highways, excessive deviation increases the risk of rollover and wastes fuel.

[MacQuinn]

In terms of safety, the deviation during straight-line driving should not be excessive, typically controlled within 10 to 15 centimeters. Otherwise, high-speed cameras may capture the violation and deduct points, posing a risk of rear-end collisions. During my driving test at the driving school, the examiner emphasized that deviations exceeding 20 centimeters would result in point deductions, and the same applies on real roads. Stay focused on the road ahead while driving and avoid distractions like using your phone. Additionally, develop the habit of checking rearview mirror positions to avoid blind spots. In poor weather conditions, maintaining smaller deviations ensures greater stability. Regular wheel alignment checks are essential to ensure precise handling.