At 55 mph, a vehicle travels about 807 feet in ten seconds. To pass safely you need more than how many feet of empty roadway ahead?

At 55 mph, a vehicle travels about 807 feet in ten seconds. To pass safely you need more than how many feet of empty roadway ahead?

• A. 800 feet
• B. 1200 feet
• C. 1600 feet
• D. 2000 feet

Answer: (C)

The key idea is knowing how much road you need to safely complete a passing maneuver at a given speed. At 55 mph, your car travels about 807 feet in ten seconds, so roughly 80.7 feet per second. A safe pass requires you to move into the oncoming lane, pass, and then return to your lane, which takes more than ten seconds—roughly about twenty seconds to complete safely. In twenty seconds you would cover about 80.7 ft/s × 20 s ≈ 1614 feet, so you’d need around 1600 feet of clear roadway ahead. Anything shorter isn’t enough to guarantee you can finish the pass safely, while 1600 feet represents the minimum distance typically needed.

The key idea is knowing how much road you need to safely complete a passing maneuver at a given speed. At 55 mph, your car travels about 807 feet in ten seconds, so roughly 80.7 feet per second. A safe pass requires you to move into the oncoming lane, pass, and then return to your lane, which takes more than ten seconds—roughly about twenty seconds to complete safely. In twenty seconds you would cover about 80.7 ft/s × 20 s ≈ 1614 feet, so you’d need around 1600 feet of clear roadway ahead. Anything shorter isn’t enough to guarantee you can finish the pass safely, while 1600 feet represents the minimum distance typically needed.