Reaction Time and Speed Tell Us How Close is Too Close

Categories // Safety First

The Dangers of Tailgating Part 1

Reaction Time

The typical person (in good mental condition; not impaired by drugs, alcohol, or fatigue) takes at least .75 seconds to recognize the need to slow or steer to avoid a collision. It then takes another .75 seconds for the brain to tell our muscles what to do and actually start doing it. Even when we are paying attention, it’s likely that our vehicle will not start slowing or turning for an entire 1.5 seconds after the car in front of us hits the brake.


The faster we are traveling, the more distance we need between vehicles to give our brain and body time to perceive and react. At 30 mph, we’re moving 44 feet-per-second. This means we will travel 66 feet before our vehicle starts to slow or change direction. At 60 mph, we’re moving 88 feet-per-second, increasing that distance to 132 feet. That’s 132 feet we will move toward the hazard without anything happening.

Considering what we know about reaction time and speed, even advanced, professional drivers need ample space between vehicles to hope for enough time to slow, stop, and/or steer out of the way. Tailgating clearly decreases the available time we have to process and implement the best possible action in that moment. Given enough time to respond, well-trained drivers can avert most hazards in any type of vehicle.

Why Do We Tailgate in Light of the Dangers?

Our own driving confidence is probably the biggest reason most of us tailgate. We’re comfortable at the wheel; every day we drive habitually and nothing bad happens. Another reason is that most of the vehicles around us are often traveling at similar speeds, creating the illusion that the cars are not moving very quickly. We are also accustomed to treating the “normal flow” of traffic as a reasonable distance between cars. However, it’s clear that limited reaction times and higher speeds can quickly transform a seemingly acceptable distance into an unavoidable, possibly tragic, outcome.

Steer Clear of Disaster by Keeping a Safe Distance

The best way to reduce high-pressure situations is to avoid tailgating altogether. What do you do to ward off potential tailgaters or avoid becoming one yourself? Check back soon for The Dangers of Tailgating Part 2. I’ll explain how to reduce your own tailgating temptation and better manage when it happens to you.

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