What is the braking distance from 40 km/h to a complete stop?

[ZoeFitz]

Under normal circumstances, the braking distance from 40 km/h to a complete stop for an unladen vehicle is approximately 45 meters. Here is some relevant information about automotive braking: 1. Braking Overview: Braking, also known as deceleration, refers to the action of stopping or reducing the speed of a moving locomotive, vehicle, or other transportation equipment or machinery. 2. Working Principle: The general principle of braking is to fix a wheel or disc on the high-speed shaft of the machine and install corresponding brake shoes, bands, or discs on the machine base, which generate braking torque under external force. The braking device is a mechanical deceleration device that can slow down the vehicle's speed, also known as a retarder.

[VanCecilia]

The other day I tried braking to a stop from 40 mph on an open stretch, and on dry pavement the car came to a halt in about 7 meters. But I noticed many factors can affect this number—like when the tire tread is worn or the brake pads are nearing replacement, the distance can stretch to 8 or 9 meters. Rainy days are the most dangerous, with slippery roads; that time I braked from 40 mph, the car slid nearly 15 meters before stopping. Vehicle weight is also crucial—lighter cars stop quicker, while a fully loaded SUV takes more effort. I always make sure to maintain the braking system, regularly check tire pressure to keep stopping distances short, and maintain at least twice the usual following distance just in case. Safety comes first—better not to tailgate.

[StCollin]

I once did a simple calculation of braking distance while driving. At a speed of 40 kilometers per hour, it converts to about 11 meters per second. With good braking force, the stopping distance is roughly the square of the speed divided by 250. 40 multiplied by 40 is 1600, divided by 250 gives approximately 6.4 meters, so under ideal conditions, it's about 6 to 7 meters. However, in actual driving, the braking action time is short, and the average speed is halved, so the distance is roughly 5 to 7 meters. There are many influencing factors, such as slight differences between concrete and asphalt roads, and older cars might increase the distance to 8 or 9 meters. In short, I remember that stopping at 40 km/h on dry roads generally falls within the range of 6 to 8 meters. It's best to test your car in a safe, open area to confirm its specific performance.

[RyderAnn]

I remember during driving school practice, the instructor had us test the braking distance at 40 km/h. I slammed on the brakes, and the car stopped after sliding 7 meters on dry pavement. The tires performed well when new, but one rainy day when I repeated the same speed braking test, it slid over 10 meters before stopping. There are also big differences between vehicles—my friend's sedan stopped quicker than the old car I was driving. For daily driving, I recommend not obsessing over theory. On sunny days, leaving 8 meters of space at 40 km/h is safe enough; double that to 15 meters on rainy days. Don't count on emergency braking to save you.