How wide does a 4.7-meter sedan need for a 90-degree turn?

[JulianRose]

The width of a one-way road should not be less than 3.5 meters. Below is relevant information about right-angle turns: 1. Overview: A right-angle turn is an assessment point in Subject 2 of the driver's test, evaluating the driver's ability to correctly operate the steering and accurately judge the inner and outer wheel differences when driving through abrupt road changes. Engage first gear, release the handbrake, slowly lift the clutch to maintain semi-linkage and move forward at a steady speed. Keep the left wiper's left dot (the first rivet) on the car aligned with the yellow line on the right edge of the road at a 20 cm distance while moving forward. Then, focus on a point slightly ahead of the middle door lock on the left front door of the car. 2. Deduction points: If the wheels touch the protruding point, it results in failure; each time the wheels touch the road edge line, 20 points are deducted; if reversing is used to complete the task, 10 points are deducted; failure to use the turn signal or incorrect use of the turn signal results in a 10-point deduction.

[CollinLynn]

I remember road width is particularly crucial when making turns in my car. My vehicle is about 4.7 meters long, so ensuring sufficient road width is essential for smooth 90-degree turns to avoid scratches. Generally, the turning radius determines the required road width—a conservative estimate is roughly 1.5 times the car's length, so 5 to 6 meters is a safer bet. I've tried making 90-degree turns on narrow roads, and when the width is under 4 meters, it feels tight, with the rear end prone to hitting objects. In practice, you also need to account for roadside obstacles like streetlights or pedestrians, leaving a half-meter margin for added safety. Urban streets are typically designed to be 6 meters wide, which handles such turns easily. When driving, always anticipate angles in advance and avoid sudden sharp turns—this protects your car and reduces accident risks.

[EleanorMarie]

From a physics perspective, the key to determining the required road width for a turn lies in the relationship between the turning radius and the vehicle length. My understanding is that for a 4.7-meter-long car, the minimum road width for a 90-degree right-angle turn should be calculated based on geometric formulas. With a typical turning radius of around 4 meters, the required road width when the diameter is 8 meters should be greater than the vehicle length plus half the wheelbase, approximately over 5 meters being reasonable. A simple formula such as road width ≈ vehicle length × 1.1 provides a baseline value. However, actual conditions are also influenced by vehicle weight and road surface – dry pavement requires more space than slippery surfaces. For measurement, you can simulate it in an open area using a tape measure for a more intuitive hands-on experience.

[BrynleeAnn]

Safety comes first, and sufficient buffer must be reserved for road width when turning. Based on my experience, a 4.7-meter-long car making a 90-degree turn requires at least 5.5 meters of road width for smooth operation to avoid scraping the curb or causing accidents. This accounts for factors like slippery roads during rain or limited visibility. Generally, it is recommended that the road width be about 1.2 times the length of the car. I remember one time when I was turning in a narrow alley with less than 5 meters of road width—I almost hit a wall, only realizing afterward that there wasn’t enough reserved space. So, it’s best to visually estimate the road width before driving to ensure there’s enough room. Extra caution is needed when driving at night.