You increase your speed from 50 km/h to 100 km/h. How does the reaction distance change in accordance with the rule of thumb?

You answered correctly. According to the German rule of thumb, the reaction distance in meters is calculated as speed divided by 10, then multiplied by 3 (Reaction Distance = (speed in km/h ÷ 10) × 3). At 50 km/h, the reaction distance is 15 meters; at 100 km/h, it is 30 meters. So, when you double your speed from 50 to 100 km/h, your reaction distance also doubles from 15 to 30 meters. This helps drivers estimate how far their car travels during their reaction time and shows why higher speeds require greater attention and longer distances to stop safely.