Speed-Time Comparison
Speed-to-Risk Comparison
Kinematic Braking Simulator Track
Visual comparison of reaction delay, braking, and stopping distance
Car A
—
Car B
—
If a barrier sat at Car A's stop point
—
Reaction distance = speed × 1.5s reaction time. Braking distance = speed² ÷ (2 × 9.8 m/s² × 0.7 friction). Metric units throughout.
Safety Insights
Reaction Time is Key
An average driver's reaction time is 1.5 seconds. At 100 km/h, you travel over 40 meters before even hitting the brakes.
Braking Distance Increases Exponentially
Doubling your speed from 50 km/h to 100 km/h doesn't double your braking distance—it quadruples it.
The "Faster is Better" Myth
On short trips, increasing speed saves very little time but significantly increases fuel consumption and accident risk.
Methodology & Sources
How the numbers above are calculated, and how the model holds up against a real test.
Time saved
Pure kinematics — no traffic, stops, or weather. Best-case estimate for both speeds equally.
time = distance ÷ speedReaction distance — linear
Grows in direct proportion to speed, since reaction time is fixed.
distance = speed × 1.5sBraking distance — quadratic
Kinetic energy (½mv²) has to be dissipated by friction — so doubling speed roughly quadruples braking distance, not doubles it. Friction coefficient 0.7 = dry asphalt, functioning brakes.
distance = speed² ÷ (2 × 9.8 × 0.7)Reality check
Does a "better" car really stop faster?
A BMW-certified instructor tested a Dacia Logan against a Lamborghini Huracán: up to 80 km/h, both stopped in almost the same distance — matching the model above, since braking there depends more on tire grip and reaction time than on the car itself.
Watch the result (3:06)Limitations: This model uses fixed reaction time and friction values — real driver reaction time and road grip vary with alertness, tire condition, and weather. It's meant to build intuition about why stopping distance scales non-linearly with speed, not to predict any single vehicle's actual stopping distance.