With an additional half second of reaction time, which percentages of rear-end crashes and all crashes can be prevented?

With an additional half second of reaction time, which percentages of rear-end crashes and all crashes can be prevented?

• A. 50% of rear-end crashes and 30% of all crashes
• B. 60% of rear-end crashes and 20% of all crashes
• C. 15% of rear-end crashes and 70% of all crashes
• D. 30% of rear-end crashes and 50% of all crashes

Answer: (A)

Reaction time and stopping distance determine whether you can avoid a crash, especially when you’re following another vehicle closely. If you have about half a second more to react, you can notice a hazard sooner and begin braking earlier, which makes a big difference in preventing collisions that happen when the car in front suddenly slows or stops. Rear-end crashes are most sensitive to this extra time because they’re often caused by not having enough distance or time to react to the lead vehicle. With an additional half second to react, you can prevent roughly half of those rear-end crashes. Since crashes of other types aren’t as dependent on reaction time, the overall impact on all crashes is smaller—about thirty percent. For context, that half-second can translate into a noticeable amount of stopping distance at typical driving speeds, giving you a safer margin to avoid a collision.

Reaction time and stopping distance determine whether you can avoid a crash, especially when you’re following another vehicle closely. If you have about half a second more to react, you can notice a hazard sooner and begin braking earlier, which makes a big difference in preventing collisions that happen when the car in front suddenly slows or stops. Rear-end crashes are most sensitive to this extra time because they’re often caused by not having enough distance or time to react to the lead vehicle. With an additional half second to react, you can prevent roughly half of those rear-end crashes. Since crashes of other types aren’t as dependent on reaction time, the overall impact on all crashes is smaller—about thirty percent. For context, that half-second can translate into a noticeable amount of stopping distance at typical driving speeds, giving you a safer margin to avoid a collision.