Speed Limits and Safe Following Distance
Mississippi Speed Limits
Know the standard limits tested on the permit exam: 25 mph in residential districts and school zones, 30 mph in business districts, 55 mph on most two-lane rural highways, and 65–70 mph on rural interstates. Always drive at a speed reasonable for conditions-rain, fog, night, or heavy traffic can make the posted limit too fast. The "basic speed law" says never drive faster than is safe for existing conditions, regardless of the posted number.
Following Distance
The three-second rule is the standard: pick a fixed object ahead (a sign or pole), and when the vehicle ahead passes it, count "one-thousand-one, one-thousand-two, one-thousand-three." If you reach the object before finishing, you are too close. Add a second for rain, a second for darkness, and more for ice or heavy loads. Large trucks need extra room because they cannot stop as quickly.
Stopping Distance and Adjustments
Total stopping distance = perception distance + reaction distance + braking distance. Speed affects braking distance dramatically-doubling speed roughly quadruples braking distance. Reduce speed in construction zones, near schools, on curves, and when road surfaces are wet or gravel-covered.
Traps: questions that ask whether you may exceed the posted limit to pass (no-never exceed the limit to pass); questions implying the posted limit is always safe (conditions control); and following-distance questions that use car lengths instead of seconds. Rule of thumb: three seconds minimum in good conditions, four or more when wet or dark, and never tailgate a truck or motorcycle.