Why do cars have steering wheels and not handlebars?

The answer to this question can be brought down to two factors namely, the rider’s comfort and the steering ratio. . The transmission of the steering for four-wheel vehicles requires a movement of the steering wheel >90°. Therefore, handle bars are less controllable. If the transmission is reduced to smaller angles, the force required for steering is increased decreasing the comfort of the rider.

Also, a passenger car or a bus has a much higher steering ratio in the order of between 12:1 and 20:1 - one complete turn of the steering wheel, 360 degrees, causes the wheels to turn 24 degrees, the ratio is then 360:24 = 15:1. Therefore requiring multiple turns of the wheel which is not possible using a handle bar as it gets locked after turning it by 90 degrees.