Roadwise States Ohio Driving lessons Stopping distance & the space cushion Ohio driving lesson · Safe Driving Tips
Stopping distance & the space cushion A 3-minute lesson from the Ohio course. Read the rules and examples, follow the handbook page references, and check your understanding before you move on.
Read time 3 minutes
Course unit Safe Driving Tips
Checkpoint questions 6
Source pages 34, 35 The space around your car is your reaction time. Stopping takes longer than most people think — first you notice, then you react, then the brakes work — so keep a cushion ahead, beside and behind you.
Space cushion The space you keep between your vehicle and other road users, giving you time to react.
Handbook p. 34 ↗ Stopping distance How far your vehicle travels, in ideal conditions, from the moment you realize you must stop until it stops.
Handbook p. 34 ↗ Know the rule
The 158-foot braking figure assumes 50 mph on dry pavement with good brakes.
Handbook p. 34 ↗ Know the rule
Keep a minimum following distance of one vehicle length for every 10 mph, or four seconds.
Handbook p. 34 ↗ The four-second count: When the rear of the car ahead passes a fixed point (sign or pole), start counting Count "one-thousand-one" through "one-thousand-four" If you reach the point before four, you're too close — slow down and count again With practice, guess the seconds to an object, then count to check Handbook p. 34 ↗ Increase following distance: When weather (fog, rain, snow) or night limits visibility On slippery roads Behind large vehicles: trucks, buses, RVs and vehicles towing trailers Behind vehicles that must stop at railroad crossings (buses, hazardous-materials carriers) Handbook p. 34 ↗ Space to the side: Don't drive next to other vehicles for long — you may be in a blind spot Don't crowd the center line; keep space from oncoming traffic Make room for merging traffic by changing lanes or adjusting speed Give extra space to pedestrians (especially children) and bicyclists When a tractor-trailer passes, move to the outside part of your lane Handbook p. 35 ↗ Know the rule
Space behind: help the driver behind keep back by holding a steady speed, signaling early, and leaving more room ahead before you slow or turn.
Handbook p. 35 ↗ Put it into practice
At 40 mph, you'd want at least four car lengths (one per 10 mph) or four seconds behind the car ahead. In rain or behind a truck, leave more than that.
A useful reminder Perception and reaction each take ¾ second to 1 second — together up to 2 seconds before your brakes even start working.
Check your understanding Read the question, decide on an answer, then open it to check the explanation. These are Roadwise study questions based on the source handbook.
What is the average perception time for an alert driver? 1/4 second to 1/2 second 2 to 3 seconds ¾ second to 1 second 3 to 4 seconds Answer: ¾ second to 1 second
The average perception time for an alert driver is ¾ second to 1 second.
Handbook p. 34 ↗ About how far does it take a vehicle to stop at 50 mph on dry pavement with good brakes? About 50 feet About 335 feet About 75 feet About 158 feet Answer: About 158 feet
At 50 mph on dry pavement with good brakes, it can take about 158 feet to stop.
Handbook p. 34 ↗ What is the recommended minimum following distance in ideal conditions? One vehicle length per 10 mph, or 4 seconds Half a vehicle length per 10 mph 10 seconds regardless of speed 2 seconds regardless of speed Answer: One vehicle length per 10 mph, or 4 seconds
The handbook recommends a minimum following distance of one vehicle length per 10 mph, or 4 seconds.
Handbook p. 34 ↗ How do you determine your following distance using the four-second method? Estimate distance by eye only Count seconds from when the vehicle ahead passes a fixed point until you reach it Measure the gap with your speedometer Count how many car lengths fit between vehicles Answer: Count seconds from when the vehicle ahead passes a fixed point until you reach it
Begin counting when the rear of the vehicle ahead passes a stationary point, and see how many seconds it takes you to reach the same point.
Handbook p. 34 ↗ When should you increase your following distance beyond the recommended minimum? Only when driving uphill Only on interstate highways When visibility is limited by weather or when it's dark Only when a car is following you closely Answer: When visibility is limited by weather or when it's dark
Increase following distance in reduced visibility, at night, on slippery roads, and behind large vehicles.
Handbook p. 34 ↗ You're driving behind a bus that must stop at an upcoming railroad crossing. What should you do? Pass it before the crossing Maintain your normal following distance Tailgate closely so you don't lose the gap Increase your following distance behind it Answer: Increase your following distance behind it
Increase following distance behind vehicles required to stop at railroad crossings, such as buses.
Handbook p. 34 ↗ Previous lesson Visual search & adjusting speed Next lesson Communicating: lights, horn & signals More in Safe Driving Tips About the source Roadwise’s Ohio course uses the driver handbook edition supplied with this study pack. This lesson cites source pages 34, 35. The linked PDF is a third-party mirror of the handbook, rather than a government-hosted page.
Open the handbook source PDF · View the source edition
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