stopping distance
Space to halt
Stopping distance is the space a vehicle needs to come to a complete halt after the driver perceives a hazard.
It combines reaction distance—how far you travel while processing the danger and moving your foot to the brake—with braking distance, which depends on speed, road conditions, and vehicle weight.
At highway speeds, stopping distance can exceed several hundred feet.
Decrease in speed
- pedalFoot-operated lever
- antilockPrevents wheels from seizing
- padsCushioned protective layers
- discsFlat circular objects
rotors · calipers · hydraulics · brake fade · ABS · emergency · footbrake · handbrake
Product of mass, velocity
- frictionResistance between touching surfaces
- velocityDirected rate of motion
- inertiaResistance to altered motion
- kinetic energyPower from movement
mass · force · drag · coefficient · kinematics · dynamics · gravity · acceleration
Following another vehicle unsafely
- bufferProtective intermediate space
- clearancePermitted passage or approval
- marginEdge of a page
- defensive drivingProactive safe vehicle operation
two-second rule · hazard · precaution · collision avoidance · rear-end · cushion · spacing
Saturated with liquid
- dryFree from moisture
- icyFrozen or unfriendly
- slipperyLacking friction, hard-to-grasp
- tractionAdhesive friction enabling movement
grip · asphalt · concrete · gravel · hydroplaning · black ice · snow · rain
Maximum legal driving pace
- highwayMajor road for travel
- intersectionPoint where paths meet
- pedestrianOne traveling afoot
- crosswalkMarked street-crossing zone
red light · school zone · congestion · freeway · merge · yield · road signs · urban
Speed of response
- alertnessActive mental awareness
- reflexesAutomatic physical responses
- perceptionMental interpretation of stimuli
- anticipationState of awaiting something
awareness · response · fatigue · impairment · distraction · intoxication · judgment · experience
deceleration
Decrease in speed
discs · rotors · calipers · hydraulics · brake fade · ABS · emergency · footbrake · handbrake
momentum
Product of mass, velocity
- frictionResistance between touching surfaces
- velocityDirected rate of motion
- inertiaResistance to altered motion
kinetic energy · mass · force · drag · coefficient · kinematics · dynamics · gravity · acceleration · collision
tailgating
Following another vehicle unsafely
defensive driving · two-second rule · hazard · precaution · collision avoidance · rear-end · cushion · spacing
wet
Saturated with liquid
traction · grip · asphalt · concrete · gravel · hydroplaning · black ice · snow · rain · tire tread
speed limit
Maximum legal driving pace
- highwayMajor road for travel
- intersectionPoint where paths meet
- pedestrianOne traveling afoot
crosswalk · red light · school zone · congestion · freeway · merge · yield · road signs · urban · residential
reaction time
Speed of response
- alertnessActive mental awareness
- reflexesAutomatic physical responses
- perceptionMental interpretation of stimuli
anticipation · awareness · response · fatigue · impairment · distraction · intoxication · judgment · experience · focus
- drivingdrive, steering, driver, acceleration, motorist
- Road Safetyseatbelt, speed limit, crosswalk, traffic light, turn signal
- driving safetyblind spot, braking, brake, signaling, merging
- Car Specshorsepower, torque, MPG, RPM, fuel economy
- road measurementsmile, kilometer, mile marker, milepost, furlong
- vehicle dynamicsacceleration, handling, steering, traction, braking