Which condition may require a driver to enter a curve at a slower speed?

Entering a curve at a slower speed is essential for maintaining control and ensuring safety when road conditions are slippery or traction is low. When roads are wet, icy, or covered in gravel, the friction between the tires and the road surface is significantly reduced. This lack of traction makes it easier for a vehicle to skid or slide out of control, particularly during sharp turns. By reducing speed before entering the curve, a driver can help maintain better handling of the vehicle, allowing for smoother navigation through the curve while minimizing the risk of losing control.

In contrast, the other scenarios do not specifically necessitate a slower approach to a curve. For example, while a sports car may be designed for high-speed performance and agility, it does not inherently require a reduction in speed under normal conditions. Approaching a toll booth may involve slowing down for the stop but is more about general awareness and preparation than an adjustment specifically for taking a curve. Similarly, having no vehicles ahead does not directly influence the need for speed adjustments; safe driving practices should always prioritize conditions over the presence or absence of other vehicles.