What is the reason for the difference in fuel consumption between national highways and expressways?
2 Answers
The reason for the difference in fuel consumption between national highways and expressways is the variation in driving speeds, which affects the rate of fuel consumption. Below is a detailed explanation regarding vehicle speed: 1. Overview: Vehicle speed refers to the distance a car travels per unit of time, commonly measured in kilometers per hour or meters per second. Vehicle speed is one of the three key parameters in traffic flow theory and holds significant importance in traffic flow studies. 2. Additional Information: Vehicle speed can also broadly refer to the speed of motor vehicles. Depending on the application, vehicle speed can be categorized into spot speed, segment speed, and design speed. Spot speed is the instantaneous speed of a vehicle passing a specific point on the road. Design speed is the speed established to determine the design parameters of various geometric elements of a road and ensure their coordination.
After years of driving, I've noticed that fuel consumption on national highways is relatively high, mainly due to frequent stops and starts causing fuel wastage. Like the last time I drove home on a national highway, I had to stop every few minutes for traffic lights or congestion, with the engine constantly switching between acceleration and braking, significantly increasing fuel consumption. On the expressway, however, the car mostly maintains a steady speed. Although higher speeds increase wind resistance, the engine operates in a more fuel-efficient RPM range, resulting in higher overall efficiency. Additionally, national highways have many curves requiring sudden turns and brakes, leading to lower kinetic energy conversion rates for the vehicle, which is another factor in higher fuel consumption. In contrast, expressways offer smoother conditions with fewer such disruptions, naturally leading to lower fuel consumption. Choosing expressways for daily driving can save a lot on fuel costs and reduce emissions.
