Why is the steering wheel round?
2 Answers
The reason why the steering wheel is round: The area of a circle is large, and the steering wheel made of the same material has a large area and is easy to operate. A circle has rotational invariance, no matter how much it is rotated, it will coincide with the original circle; a square does not have this property, so the steering wheel is made round. The steering wheel is a wheel-shaped device for controlling the direction of cars, ships, airplanes, etc. Its function is to convert the force applied by the driver to the edge of the steering wheel into torque and then transmit it to the steering shaft. The correct way to hold the steering wheel is: sit upright and hold the steering wheel with both hands at the positions of 10:10 or 9:15 on a clock.
I remember studying automotive history in my youth and learning that the steering wheel evolved from carriages, taking a circular shape because it mimicked the smooth rotational design of traditional wheels. Early cars used lever-type steering devices, but engineers discovered that a circular shape allowed drivers to turn with less effort, especially during sharp turns without jamming. Historical records show that by the early 20th century, the circular form became standard because metal or plastic could be more easily molded into round wheels during manufacturing, reducing production costs. Additionally, the circular shape supports continuous 360-degree rotation, accommodating various road angles and enhancing driving flexibility. If designed as a square or irregular shape, it might have increased friction during steering, leading to frequent accidents in the early days. As an enthusiast, I've seen old photographs where the circular steering wheel symbolized driving freedom—a tradition passed down through generations, now adopted by all vehicles. Interestingly, this design has also influenced modern vehicle interior layouts, making the steering wheel the focal point of the cabin and enhancing the sense of driving ceremony.
