A standard safety practice dictating that a driver should stay at least two full seconds behind the vehicle directly in front. It provides the minimum necessary reaction time to apply the brakes or take evasive action if the lead vehicle stops suddenly.
Heard on the job
You're tailgating that semi, back off and remember the two-second rule.
Related terms
Braking time
The chronological duration required to bring a moving vehicle to a complete stop once the pedal is pressed.
Active braking time
The exact duration that brake pads are applying friction to the rotors during a stop.
ADAS
Advanced driver-assistance systems that use sensors and cameras to improve vehicle safety.