Core: The 2-second rule: fixed point, counting, formula

You must be able to bring your vehicle to a stop within the distance you can see and that is clear. There is no exact number written in the law. The book translates that open norm into a practical rule of thumb: at least 2 seconds of following distance (Book p.123). You check this using the fixed-point method: as soon as the car ahead passes a clear marker (a post, lamppost, bridge pillar), you count out loud until you reach that same point. If you want this expressed in metres, the book gives a rule of thumb: divide the speed in km/h by 2 and add 10%. At 50 km/h: (50:2)+10% = 27.5 m. At 80 km/h: (80:2)+10% = 44 m. At 100 km/h: (100:2)+10% = 55 m.