Vehicle dynamics on pavements: The distance indicated by wheel revolutions that exceeds the true ground distance travelled is termed…

Introduction / Context:
Understanding slip and skid helps diagnose traction, braking, and surface conditions on pavements. These phenomena affect stopping distances, tire wear, and collision risk, and inform design choices for gradients, surface textures, and drainage.

Given Data / Assumptions:

• A wheel’s revolution count is used to estimate distance.
• Measured “revolution distance” is greater than the true ground distance covered.
• Normal driving (not locked-wheel emergency braking) is implied.

Concept / Approach:

Slip occurs when the drive wheels rotate faster than the ground distance warrants (for example, on an upgrade or low-friction surface), so the indicated distance by rotations is larger than actual. Skid occurs when wheels slide with little or no rotation (for example, under heavy braking), so the actual distance travelled exceeds what wheel rotations indicate.

Step-by-Step Solution:

Verification / Alternative check:

On steep upgrades or on snow, tires may spin; odometers over-read distance, matching the definition of slip. During braking with wheel lock, the odometer under-reads; that is characteristic skid.

Why Other Options Are Wrong:

• Skid: opposite sign; wheels rotate less than distance.
• Neither / Both: definitions are mutually exclusive for a given instant.

Common Pitfalls:

• Using the terms interchangeably; they reflect different tire–pavement interactions.
• Ignoring surface macrotexture and microtexture effects on traction.

Final Answer:

Slip.