Which road surface is likely to provide the least traction?

Gravel surfaces typically provide the least traction among the options listed. This is primarily due to the loose nature of gravel, which consists of small stones that aren't compactly bound together. When a vehicle travels on gravel, the tires can sink into the loose material, leading to a reduced connection between the tires and the surface. This scenario can significantly impair the ability of the vehicle to maintain traction, especially during turns, sudden stops, or inclement weather conditions.

In contrast, pavement, concrete, and asphalt are solid surfaces that offer a more stable and consistent traction experience. They are designed to support the weight of vehicles and provide better grip due to their solid, interlocking structures. These surfaces have higher friction coefficients, allowing for better acceleration, braking, and cornering performance, which is crucial for safe driving. The differences in surface composition and design are key to understanding why gravel lacks the traction of the other surfaces.