Why is the speed limit on the Hedong-Dalian Expressway set at 80 kilometers per hour?

[Penny]

The speed limit on the Hedong-Dalian Expressway is set at 80 kilometers per hour only in certain sections, primarily due to technical conditions affecting interchange areas and tunnel sections. The design speed of the Hedong-Dalian Expressway is 100 kilometers per hour, with speed limits of 80 kilometers per hour in areas such as the curved section of the Dongjiagou Interchange and the Jinshan Tunnel. Relevant information about the speed limit is as follows: 1. Introduction to speed limits: Speed limits generally refer to the regulation of vehicle speeds within a certain numerical range over a specified distance of road. 2. Purpose of speed limits: The main purpose is to pre-warn drivers to reasonably control their speed in subsequent sections ahead, prevent the dangers of speeding, and ensure driving safety. Speed limits are an indispensable and most important aspect of road transportation safety.

[OTimothy]

I think the speed limit on the He-Da Expressway is set at 80 kilometers per hour mainly because that section is mountainous with many sharp turns, making it particularly dangerous to drive. For example, in areas with tight curves, driving too fast can easily lead to skidding or loss of control. I drove there once last year, and with heavy fog reducing visibility, driving slower was the only way to stay safe. Additionally, during times of heavy traffic, the speed limit helps reduce rear-end collisions and prevents gridlock. The government set this speed limit for everyone's benefit—safety comes first. Highway maintenance also plays a role; driving slower reduces the risk of tire blowouts on uneven roads or near construction zones. Overall, this isn’t an arbitrary decision—it’s based on actual road conditions and accident data. Everyone should comply and not risk their lives just to save time.

[MacLeah]

With decades of experience driving on highways, I find the 80 km/h speed limit on the He-Da Expressway particularly reasonable. The terrain there is complex, with steep slopes in mountainous areas, making vehicle control difficult when speeding. I've witnessed several rollover accidents, all caused by excessive speed. Weather conditions also play a crucial role; during winter ice or rainy slippery conditions, slowing down is the golden rule. Speed limits are also related to traffic density. During peak hours with heavy traffic, if everyone drives a bit slower, the overall flow becomes smoother with fewer minor collisions. In the long run, such design extends the road's lifespan and reduces maintenance costs. In summary, adhering to speed limits isn't about being rigid; it's a wise choice.

[BrodyDella]

From an engineering perspective, the 80 km/h speed limit on the He-Da Expressway is scientifically designed. The road has small curve radii and steep gradients, where high speeds would increase centrifugal force and raise rollover risks. Considering braking distance requirements—such as ensuring sufficient buffer zones on curves—the 80 km/h limit guarantees safe stopping distances. Weather sensors also monitor conditions, automatically triggering slowdown warnings during rain or fog. These parameters are based on real-world testing to mitigate potential hazards. During maintenance, the speed limit protects workers on the roadway. Overall, technical details substantiate this speed limit value.