What is the principle of vehicle speed measurement?
2 Answers
Vehicle speed measurement principle: The average speed measurement system is achieved through an automatic license plate recognition system. Two adjacent monitoring points are set up on the same road section to record the time when a vehicle passes through these two points, thereby calculating the vehicle's average speed on that section. Based on the speed limit standard of that section, it determines whether the vehicle has committed a speeding violation. Methods to safely pass through an average speed measurement zone are as follows: 1. If you see a sign indicating "Average Speed Measurement Zone" by the roadside, reduce your speed to the specified limit and drive within the speed limit to pass safely. 2. If you exceed the speed limit at the starting point of the measurement, you should try to maintain an average speed below the specified limit throughout the measurement section. As long as the calculated average speed does not exceed the specified limit when reaching the end point, you will not be judged as speeding.
After driving for over a decade, I finally understood how the speedometer works. Simply put, a sensor counts the rotations of the wheels or transmission, then calculates the actual distance traveled based on your car's tire size. This number is sent back to the dashboard to display the speed. Later, I discovered that GPS can also measure speed by calculating how fast you're moving based on satellite positioning. However, it's important to note that the actual speed might be 5 to 10 km/h lower than what's shown, as manufacturers intentionally set it slightly higher to leave a margin for safer driving. When cruising on the highway, I prefer to compare the speed with my phone's navigation for better accuracy.
