What is the safe following distance at 100 km/h on the highway?

[LeonardoLynn]

On the highway, the safe following distance at 100 km/h should be over 100 meters. Below are specific guidelines for high-speed driving: 1. Pre-drive vehicle inspection: Before entering the highway, check the braking system and tire pressure/wear condition. This prevents insufficient emergency braking and ensures optimal tire pressure (both underinflation and overinflation are hazardous for high-speed driving and may cause blowouts). 2. Seatbelt usage: All occupants, including rear-seat passengers, must wear seatbelts during high-speed driving, regardless of road type. 3. Lane discipline: Highway lanes are clearly marked for specific vehicle types (e.g., large vehicles, passenger cars). When overtaking, return to your designated lane promptly after completing the maneuver—avoid prolonged occupation of other lanes.

[AdelineLynn]

As an experienced driver with over a decade of highway driving, I always prioritize maintaining a safe following distance when driving at 100 km/h. I typically use the three-second rule: pick a fixed point like a roadside tree or sign, start counting one, two, three when the car ahead passes it, and if I pass the same point before finishing, I'm too close. At 100 km/h, the distance should be about 85 meters, roughly the length of 10 cars, which provides enough space to avoid a collision during emergency braking. On highways, higher speeds mean shorter reaction times—I’ve witnessed rear-end collisions caused by insufficient distance. Especially in rain or fog, when roads are slippery and braking is less effective, I double the distance to over 160 meters. Safety is far more important than saving time, and making this a habit can be lifesaving.

[SanLouis]

I remember when I first learned to drive, I was always nervous on the highway. My instructor told me to use the three-second rule to maintain a safe distance when driving at 100 km/h, which is about 80 meters. The method is simple: pick a fixed point like a bridge pillar, and after the car in front passes it, count three seconds in your mind before reaching that point yourself. Now I also use a mobile app to remind me not to follow too closely to avoid sudden braking. Once during light rain, I got distracted and followed too closely, almost rear-ending a small truck ahead. Luckily, I had left enough space to brake in time. Since then, I've become more cautious when driving, and with good habits, everything goes smoothly.

[OOmar]

As a tech enthusiast, I really love the adaptive cruise control feature in new cars, which automatically adjusts the following distance within a safe range. But when driving an older car, I rely on the three-second rule: at 100 km/h, I maintain a distance of about 85 meters by counting three seconds after the car ahead passes a road marker. Although electronic devices are great, they can fail, so calculating it myself feels more reliable. In rainy conditions, I increase the distance to one and a half times—safe driving ultimately depends on my own control.