{"uid":"cap_af7uZvWG2yD0nZ6zhmjaF","slug":"automotive-stopping-distance-calculator-f3a1fbff","name":"Automotive Stopping Distance Calculator","description":"Stopping distance from speed: reaction distance plus braking distance on dry, wet, snow or ice, with road grade.","url":"https://automotive-calc.x402tookit.com/stopping-distance?utm_source=zero.xyz","method":"GET","headers":{},"bodySchema":{"type":"object","$schema":"https://json-schema.org/draft/2020-12/schema","required":["input"],"properties":{"input":{"type":"object","required":["type","method"],"properties":{"type":{"type":"string","const":"http"},"method":{"enum":["GET"],"type":"string"},"queryParams":{"type":"object","required":["speed"],"properties":{"unit":{"type":"string","description":"mph (default) or kmh"},"speed":{"type":"number","description":"Speed, 1 to 250"},"surface":{"type":"string","description":"dry-asphalt (default, friction 0.7), wet-asphalt (0.4), snow (0.2) or ice (0.1)"},"friction":{"type":"number","description":"Or a friction coefficient, 0.05 to 1.2 (replaces surface)"},"gradePercent":{"type":"number","description":"Road grade in %, -20 to 20 (positive uphill shortens braking, negative downhill lengthens it)"},"reactionSeconds":{"type":"number","description":"Driver reaction time in seconds, 0 to 4 (default 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total stopping distance (reaction distance + braking distance) for a given speed, road surface condition, and grade.","exampleAgentPrompt":"What's the total stopping distance for a car traveling at 65 mph on wet asphalt on a -3% downhill grade, assuming a 1.5-second reaction time?","exampleUseCases":[{"title":"School zone safe following distance check","prompt":"I'm doing 25 mph on a snowy residential road — what's my total stopping distance, reaction included, so I know how far back to stay from the car ahead?"},{"title":"Highway safety margin on rain-slick road","prompt":"Calculate my stopping distance at 70 mph on wet asphalt with a 2-second reaction time — I want both the reaction distance and braking distance separately."},{"title":"Mountain descent braking analysis","prompt":"I'm heading down a steep mountain road at 45 mph with a -10% grade on dry asphalt — how much more stopping distance do I need compared to flat ground?"}],"resultDescription":"Returns total stopping distance in both meters and feet, broken down into reaction distance and braking distance, along with deceleration in g-force, stopping time in seconds, the friction coefficient used, speed in mph/kmh/m·s⁻¹, surface type, road grade, and a human-readable summary and disclaimer.","failureModes":["Missing required 'speed' parameter returns an error","Speed outside 1–250 range is rejected","Friction coefficient outside 0.05–1.2 range is rejected","Invalid surface string not matching enum returns an error","Grade percent outside -20 to 20 range is rejected","Invalid unit string (not 'mph' or 'kmh') may use default or return error"],"whenToPreferThis":"Use this endpoint when you need a physics-based stopping distance calculation that accounts for road surface friction (dry, wet, snow, ice, or custom coefficient) and road grade, with separate reaction and braking distance components. Prefer it over generic lookup tables when road conditions or slope matter, or when you need values in both metric and imperial units simultaneously.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-10-30T07:02:35.290Z","isFirstParty":false,"canonicalSlug":"automotive-stopping-distance-calculator-f3a1fbff"}