Speed and Following Distance Flashcards

A driver enters a school zone at 35 mph when the posted limit is 15 mph. In a hazard perception context, which risk is most immediately elevated?

Answer: Inability to stop in time for a child stepping off the curb

At 35 mph, stopping distance is far greater than the short distances typical in school zones, meaning a child stepping into the road could not be avoided.

What effect does increasing speed have on a driver's peripheral vision?

Answer: It narrows peripheral vision, creating a tunnel-vision effect

As speed increases, drivers naturally focus further ahead, causing peripheral vision to narrow, which means roadside hazards are more easily missed.

In a hazard perception test clip, a vehicle is following a cyclist at 40 mph with a 1-second gap. Why is this especially dangerous?

Answer: Cyclists can stop faster than cars and the driver has no time to react

Cyclists can brake sharply, and at 40 mph with only a 1-second gap the driver has nowhere near enough distance to stop before hitting the cyclist.

What is the relationship between speed and the severity of a collision if a crash does occur?

Answer: Higher speeds result in exponentially greater impact forces and injury severity

Kinetic energy (and thus impact force) increases with the square of velocity, so even small increases in speed dramatically worsen crash outcomes.

A driver on a highway notices the car ahead slowing due to congestion. The driver is traveling at 65 mph with a 2-second gap. What is the safest immediate action?

Answer: Gently begin braking and increase following distance before traffic fully stops

Proactively increasing the gap and beginning to reduce speed gives more buffer to stop safely, whereas maintaining speed or making sudden moves creates additional hazards.

On a highway where traffic is moving at 70 mph, a driver leaves only a 1-second gap behind the vehicle ahead. How many feet approximately does this gap represent?

Answer: Approximately 103 feet

At 70 mph, a vehicle travels roughly 103 feet per second, so a 1-second gap leaves only 103 feet — far less than the 300+ feet typically needed to stop from 70 mph.

Which of the following best explains why speed management is tested in the Hazard Perception Test?

Answer: Inappropriate speed is one of the leading contributing factors in fatal and serious road crashes

Speed directly determines both the likelihood of a crash occurring and the severity of injuries if one does; it is therefore a central element of hazard perception and road safety education.