Turn signal — all roads300 feet before
Lane-change signal300 feet before
Following distance3-second rule
Following — bad weather4-second rule (or more)
School bus stop distance20 feet minimum
No passing — bridge / tunnel100 feet
No passing — RR crossing100 feet
Dim headlights (oncoming)500 feet
Dim headlights (following)200 feet
High beam range / Low beam350 ft / 100 ft
Tail / brake lights visible500 ft / 100 ft
Horn audible from200 feet
Pass cyclist clearance3 feet minimum
RR crossing stop range15–50 feet from rail
Don't follow emergency vehicleWithin 500 feet (lights on)
💡 Headlights are required from sunset to sunrise, any time visibility is less than 1,000 feet, and any time windshield wipers are in use (p. 60). At 55 mph for 3–4 seconds your vehicle covers the length of a football field — leave room.