If driving conditions are not normal or the driver is impaired, what should be considered when determining a possible perception/reaction time?

• A. Use a fixed standard time regardless of condition
• B. Decrease the estimated perception/reaction time
• C. Increase the estimated perception/reaction time
• D. Ignore the condition and use standard time

Answer: (C)

When conditions are not normal or the driver is impaired, perception and reaction take longer. Hazards become harder to notice and interpret due to reduced visibility (rain, fog, glare, nighttime), poor road surfaces, or distractions, fatigue, or intoxication. Because processing the information and initiating a response is slower in these situations, you should increase the estimated perception/reaction time to reflect that delay. This adjustment leads to a more accurate and safer stopping distance, helping you maintain a safer following distance. Using a fixed standard time or ignoring the condition would underestimate how long it takes to respond, which raises the risk of a crash.