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.
A posted speed limit is the fastest you may go in ideal conditions — dry road, good visibility, normal traffic. When conditions get worse, the safe (and legal) speed drops below the number on the sign.
Know the rule
Speed limits assume the road's design, the expected traffic volume, and dry weather without fog or other visibility problems.
You're on a 55 mph freeway inside a city when heavy fog rolls in and you can only see a few car lengths. Driving 55 would be illegal if you couldn't stop within the distance you can see. Slow until you can.
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.
Regardless of the posted speed limit, what does Ohio law require regarding stopping distance?
Stop within the assured clear distance ahead
You must always drive at least the posted limit
You may exceed the limit if traffic is light
Stopping distance is not regulated by law
Answer: Stop within the assured clear distance ahead
Ohio law prohibits driving faster than a speed that allows you to stop within the assured clear distance ahead.
