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About this tool
Check monsoon readiness: wet stopping distance from tread depth, aquaplaning speed from tyre pressure and a weighted pre-rain checklist.
A monsoon driving readiness checker turns two measurements — tread depth and cold tyre pressure — into the numbers that decide a wet-weather stop. Braking distance is computed as v²/(2μg) with a wet friction coefficient chosen from your tread depth, reaction distance uses a 1.5-second wet reaction time, and the aquaplaning onset speed comes from the NASA rotating-tyre formula V = 9√p knots (Horne & Dreher, TN D-2056). A weighted eighteen-point checklist covers everything a gauge cannot measure.
Open Monsoon Driving Readiness Checker on AltFTool — it loads instantly in your browser.
Add your input to the workspace.
Adjust the options until the result looks right.
Copy or download the output and put it to work.
Reports the actual extra metres your worn tread costs at your cruising speed.
Uses the published NASA formula rather than a generic 'slow down in rain'.
A dead wiper or an untested brake stops the checklist instead of costing a few points.
1.6 mm in the principal grooves for passenger cars, set by Rule 94 of the Central Motor Vehicles Rules. That is a legal floor, not a safe one — wet grip falls away below about 3 mm, which is where most tyre makers advise replacement before a monsoon.
For a rotating tyre the onset speed in knots is roughly nine times the square root of the inflation pressure in psi, so about 94 km/h at 32 psi and only about 85 km/h at 26 psi. Because the speed scales with the square root of pressure, an under-inflated tyre starts floating noticeably earlier — which is why weekly cold pressure checks matter more in the rains.
Typically 50% to 70% longer than on dry tarmac at the same speed. From 80 km/h a car with healthy tread needs roughly 54 m dry and about 84 m wet, because the friction coefficient drops from around 0.8 to 0.5 and rain adds about half a second to reaction time.
No. Hazard lights disable or mask your indicators on most cars, so nobody can tell when you are about to change lane or turn, and a stationary-hazard signal on a moving car confuses everyone behind you. Use headlights on low beam, or fog lamps if fitted, and slow down instead.