
First-class roads have a speed limit of 60-100km/h for cars. Below are detailed explanations about 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. It is one of the three key parameters in traffic flow theory and holds significant importance in traffic flow studies. 2. Others: Vehicle speed can also broadly refer to motor vehicle speed. Depending on different purposes, vehicle speeds are mainly categorized into spot speed, section 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 set to determine design indicators for various geometric elements of the road and ensure their coordination.

I often drive long distances, and the speed limits on primary roads are quite nuanced. For regular passenger cars, most sections are limited to 100 km/h, but when passing through villages, school zones, or areas with many curves, the limit may drop to 80 or even 60 km/h. Pay special attention to speed limit signs on national highways with double solid lines or provincial highways with many heavy trucks—exceeding by just 10% could land you a ticket. Once, my navigation alerted me to a speed camera ahead, and the limit suddenly dropped from 100 to 70 km/h—I almost didn’t brake in time. I recommend using real-time navigation apps, as they alert you to speed limit changes. Special sections like tunnels and bridges often have lower speed limits, so don’t assume you can maintain the highest speed throughout your journey.

Last time when accompanying a friend to pick up his new car, I specifically checked the speed limit rules for first-class highways. For these bidirectional four-lane roads with central dividers, the speed limit is generally around 100 km/h, but it depends on the specific road grade. I remember the traffic regulations stating that you should drive at the design speed if there are no special signs, but it's best to automatically reduce speed by 20% on rainy days. The most annoying part is when temporary speed limit signs suddenly appear on certain sections. Last week, I passed a zone with a 40 km/h limit, and the car behind almost rear-ended me. I recommend maintaining a safe distance and easing off the throttle when you see yellow speed limit warning signs.

Right after getting my driver's license, the instructor repeatedly emphasized: when you see road signs indicating national highways starting with 'G', the speed limit is 100 km/h; for provincial roads starting with 'S', it's 80 km/h. However, in actual driving, you'll notice that many first-class roads have segmented speed limits based on road conditions. I prefer driving 10 km/h below the maximum speed limit, which saves fuel and is safer. Experienced drivers often observe the density of speed limit signs—when these signs are closely spaced, extra caution is needed. Driving on first-class roads at night requires even more vigilance. Overtaking on unlit sections can lead to misjudging speed, and downhill sections pose a higher risk of losing control.

Last time on a car forum, I saw owners debating the speed limit on first-class roads. Some said the maximum was 120 km/h, but they were actually mistaken. The roads where you can drive up to 120 km/h are highways, while the maximum speed on first-class roads is 100 km/h. I specifically checked the traffic regulations: a first-class road is defined as a trunk road with at least two lanes in the same direction. What's most important to note is that the speed limit for large vehicles is 20 km/h lower than for small cars. Following behind a large truck can easily make you overlook the speed limit changes. Always slow down in advance when approaching curves. Last week, a novice driver maintained 100 km/h on a provincial road curve and ended up crashing through the guardrail. During the rainy season, when the road surface is slippery, even 80 km/h can lead to skidding.

Ten years of driving experience summarized: So-called first-class roads refer to the main arteries of national and provincial highways, where the speed limit for cars is generally 100 km/h. However, the key point isn't how fast you can go, but rather how slow you should go – vehicles traveling 20% below the speed limit (turtle-speed cars) are actually more dangerous. I've encountered situations where a car in the passing lane was going 60 km/h, resulting in a rear-end collision from following traffic. Also pay attention to special time period speed limits, such as reduced limits to 80 km/h during foggy conditions or at night. Speed cameras love to hide at transitions between uphill and downhill sections and after curves – there are many spots not reported by navigation systems. Remember: speeding within 10% gets you a warning, exceeding 20% means points deducted and fines – don't count on luck.


