¿En qué caso es mayor la distancia de detención?

The stopping distance is longer when the carriageway is wet, because this makes the road surface more slippery and reduces the tyres' grip on the road. On a wet carriageway, a vehicle needs a longer distance to come to a complete stop after braking than on a dry one. This is because the friction between the tyres and the road is lower in wet conditions, which increases the time and distance needed to stop safely. So when driving in the rain, it is important to increase your safe distance and reduce your speed to make up for the longer stopping distance and drive safely.