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Speed & Stopping Distances · Topic 4 of 6 · ~1 min read
What Changes Your Numbers
In this lesson you'll learn
- The one variable — friction — through which almost every condition attacks your braking distance, and how to reason about it with the f-coefficient
- The wet-season picture: steady rain, the first-rain oil film, and standing water as three different problems
- What murram does to the friction framework — and why "unpredictable" is the technically accurate description
- The vehicle-side multipliers: tread depth, tyre pressure, brake condition, and load
- How the multipliers stack — the sobering arithmetic of a wet night on worn tyres
- 1. One Variable to Rule Them: FrictionUse the friction coefficient to reason about how any surface changes braking distance.
- 2. The Wet Season: Three Distinct ProblemsDistinguish steady rain, the first-rain oil film, and standing water as three different grip problems.
- 3. Murram: The Surface That Won't Hold StillExplain why murram's grip is defined by variance, and set speed for the worst plausible patch rather than the average.
- 4. The Vehicle-Side MultipliersExplain how tread depth, tyre pressure, brake condition, and load each lengthen braking distance.
- 5. Gradient, and How the Multipliers StackExplain how a descent lengthens stops, and how conditions combine so no single factor looks extreme but the stack is.