Slowing down before entering a curve is the best approach because it allows for better control of the vehicle. When approaching a curve, reducing speed helps maintain traction between the tires and the road surface, which is crucial for navigating the turn safely. By decelerating beforehand, drivers can adjust their steering, ensuring they remain on their intended path without risking skidding or losing control.
Maintaining a constant speed might seem reasonable, but if the speed is too high, it can lead to an inability to properly navigate the curve, increasing the risk of an accident. Speeding up before entering a curve would also increase the chances of losing control due to too much centrifugal force acting on the vehicle. Finally, braking hard while in the curve can lead to skidding, as it disrupts the vehicle's balance and traction, further complicating the handling of the curve. Therefore, slowing down before the curve is the safest and most effective method for handling curves while driving.