Why is the speed change lane at the highway exit called that?
2 Answers
Highway exit speed change lanes are deceleration lanes. Here is expanded information about acceleration and deceleration lanes: 1. Acceleration lane: A speed change lane designed to ensure vehicles entering the main road can safely accelerate to achieve the necessary merging distance before joining traffic. After entering the ramp, vehicles use the acceleration lane to increase speed while looking for a safe gap to merge. 2. Deceleration lane: A speed change lane designed to provide sufficient distance for vehicles exiting high-speed traffic to safely slow down before entering lower-speed lanes. While serving a similar purpose to acceleration lanes, deceleration lanes are specifically for vehicles to reduce speed after leaving high-speed traffic flow.
I've driven long-haul trucks for over a decade, and every time I exit the highway, I rely on this dedicated deceleration lane. It acts like a buffer zone, allowing vehicles traveling at high speeds to gradually slow down. On the highway, everyone drives fast, and without this specially designed exit section, sudden braking could easily cause a chain-rear-end collision. Deceleration lanes are typically 300 to 400 meters long, providing enough distance to reduce speed from 120 km/h to around 60 km/h, ensuring a smooth transition onto the ramp. Especially for large trucks weighing 20 to 30 tons, their significant inertia requires more distance to slow down. This design protects the vehicle's braking system, preventing brake pads from overheating and failing, and also avoids the dangers caused by sudden lane changes. The development of highways to this day has incorporated these safety details based on accumulated lessons.
