The delay between the time that you apply the brakes to when the car actually stops is determined by road conditions, and friction on the road. Friction is a force that occurs when two objects rub together. Friction always acts to oppose the movement of an object. A vehicle with good brakes and tyres, after braking, is able to stop at approximately 7 m/s 2
A dry road enables good friction between the road and tyres, which helps to stop the vehicle faster.
A wet road has less friction between the tires and the road, resulting in more time being taken to stop the car.