Why does traffic congestion occur on highways?

[MaliaLee]

Reasons for highway traffic congestion include: 1. Toll-free holidays on highways greatly stimulate car owners' enthusiasm for self-driving travel; 2. Accidents ahead on the highway prevent vehicles from passing; 3. Road construction on certain sections of the highway; 4. Severe weather conditions that prevent all vehicles from driving at high speeds, turning the highway into a low-speed road. Traffic congestion has become a common problem in modern society, especially in developing countries, significantly affecting people's work efficiency and social development. From traffic congestion, a culture of congestion has emerged, attracting people's attention and research. Highways are multi-lane roads exclusively designed for directional and lane-specific vehicle travel, with full access control. The average annual daily traffic volume on highways should ideally exceed 15,000 passenger cars, with a design speed of 80 to 120 kilometers per hour.

[WestonFitz]

I totally get the frustration with highway traffic jams! Last weekend, it took me two extra hours to get back from the suburbs. Normally, three lanes can handle the flow, but during holidays, the traffic doubles. One tap on the brakes by the car in front can cause a three-kilometer backup. The most infuriating part is those reckless lane changers cutting in line, forcing everyone in the lane to slam on their brakes. And don’t get me started on new drivers going 40 km/h in the fast lane, holding up a whole line of cars. The highway exit ramps are another headache—often squeezing four or five lanes down to two, creating a bottleneck. Tunnels? Forget about it. Where the speed limit is 80 km/h, there’s always someone crawling at 50 km/h, causing a long queue before the entrance. On the bright side, navigation apps are pretty smart now, giving you a 30-minute heads-up to avoid red congestion zones.

[McMiles]

Highway congestion actually follows certain patterns. Holidays are definitely the worst, especially during those days with toll-free passage. During morning and evening rush hours, the main jams occur at toll stations on the urban-rural fringe, where queues of vehicles waiting to pay can block the main lanes. Terrain also plays a role—long uphill sections slow down trucks, forcing all following cars to reduce speed. Construction zones are the deadliest, with three lanes merging into one; just past the traffic cones you'll see twenty cars ahead suddenly braking with red lights blazing. A logistics friend who frequently drives says truck convoys are another major source of congestion—when two big rigs drive side by side in the passing lane for five minutes, it immediately creates a three-kilometer backup. The most dreaded scenario is chain-reaction collisions—even a minor bumper tap can create traffic stretching between two cities.

[DelCayden]

A couple of days ago, while stuck in traffic before the ring expressway tunnel, I came to a realization: traffic congestion is essentially a butterfly effect. When the car ahead changes lanes without signaling, five cars behind hit the brakes, and by the time the tenth car brakes, the entire lane comes to a standstill. The key factor is following distance—it's most dangerous when driving at 80 km/h in a 120 km/h zone while tailgating. Heavy rain makes it even worse, with all vehicles slowing down by 30%, instantly saturating road capacity. Experienced drivers know that trucks are especially numerous at the beginning and end of the month—when encountering stretches crowded with large vehicles, it's best to switch navigation routes immediately. During rain, seeing water mist ahead indicates stagnant traffic, so ease off the accelerator promptly. Service area entrances often become choke points, with holiday queues stretching three kilometers being nothing unusual.

[DelLilah]

As a long-haul truck driver who frequently travels across provinces, I've concluded that trucks have a significant impact on traffic congestion. When empty, we can go up to 90 km/h, but when fully loaded on uphill roads, our speed drops to 40 km/h, holding up dozens of cars behind us. At 5 a.m., the service areas have long queues for refueling, and trucks occupying the emergency lanes pose serious dangers. Now, with many provincial toll stations removed, congestion has worsened, especially when ETC recognition fails and vehicles block the lanes. The section of the national highway connecting to the logistics park near the expressway entrance is always packed, with ten truck lines squeezing into three lanes, and the exhaust fumes are overwhelming. When stuck in traffic due to accidents, I tune into the Truck Radio Alliance channel, which provides updates on road conditions ten minutes faster than mobile navigation apps.