What do fixed-point speed measurement and section speed measurement mean?
2 Answers
Fixed-point speed measurement refers to the speed of a vehicle passing a specific point, while section speed measurement determines the time a vehicle enters the starting point of a fixed distance and the time it exits that distance. The function of speed measurement devices: The purpose of highway speed measurement devices is to measure the driving speed of vehicles. If the speed limit is 60 and the captured speed is 90, exceeding the speed limit by more than 30% but less than 50%, a fine will be imposed, and 6 points will be deducted. Most speed capture devices currently consist of two parts: a microwave speed radar (using the Doppler effect with narrow-angle detection) and a video capture device, which work together to complete the capture. Due to technological and cost factors, most capture devices have matching issues between the response time or optimal shooting area and the speed measurement zone of the microwave radar, typically with the photo zone being closer and the speed measurement zone farther away. The principle of vehicle speed measurement: The speed of a moving object is calculated by measuring the frequency shift of the received reflected waves, usually using radar. In addition, other methods of vehicle speed measurement include loop speed measurement, video speed measurement, microwave radar speed measurement, and acoustic speed measurement. Loop speed measurement uses induction loops buried under the road surface, which is highly accurate but requires significant construction effort and must be redone if the road surface is altered. Video speed measurement involves computer analysis of captured images to determine the vehicle's route and behavior, enabling the capture of traffic violations. This method is not restricted by road conditions and is easier to install, but it is more affected by weather conditions.
When driving on the road, I often encounter these two types of speed measurement methods, and I need to explain them to you. Fixed-point speed measurement is when the camera is fixed at a certain point on the roadside, such as under a bridge or at an intersection. When your car passes that point, it clicks and directly captures your current speed to see if it exceeds the limit. Simply put, it detects instantaneous speed. Average speed measurement is different. It is installed at the start and end points of a road section, recording the time you enter the first camera and exit the second camera, calculating your average speed over that stretch of road. For example, on a several-kilometer-long stretch of highway, the system will calculate how many minutes you took. If it's too fast, it means you were speeding. Last time on the highway, I almost got a ticket because I didn’t pay attention to the average speed measurement, so now I use cruise control to maintain a steady speed. Both types of speed measurement are set up for safety, reducing accidents caused by speeding. But to deal with average speed measurement, you can’t just brake temporarily; you have to follow the rules the entire way. When driving, pay more attention to roadside signs and slow down in advance to avoid regret. After forming this habit, now whenever I see those signs, I automatically adjust my speed, and life has become much more stable.
