During a safety compliance review, an investigator examines telematics data from a commercial vehicle traveling at 55 mph on a dry highway. The driver diverted attention to a hand-held mobile device for 4.5 seconds to read a dispatch text before looking back at the road and recognizing a stalled vehicle. Which statement accurately describes the vehicle's movement and distraction profile during those 4.5 seconds?
- AThe vehicle traveled only within its baseline 1.5-second reaction distance (about 121 feet) because cognitive processing delays do not add physical travel distance before braking.
- The vehicle traveled approximately 363 feet—greater than the length of a football field—without active visual monitoring, while the driver engaged visual, manual, and cognitive distractions simultaneously.Cevap
- CThe incident represents solely an isolated cognitive distraction because reading text does not involve manual or visual diversion once the screen is visible.
- DThe vehicle's mechanical braking distance doubled during the 4.5 seconds, while perception distance remained unaffected.
Cevap
The vehicle traveled approximately 363 feet—greater than the length of a football field—without active visual monitoring, while the driver engaged visual, manual, and cognitive distractions simultaneously.
At 55 mph, a commercial motor vehicle travels approximately 80.7 feet per second. In 4.5 seconds of inattention, the vehicle travels roughly 363 feet (longer than a 360-foot standard football field with end zones) with zero hazard monitoring. Under FMCSA guidelines, reading or sending mobile text messages combines visual, manual, and cognitive distractions, making it one of the most hazardous in-cab behaviors.
Adım Adım Çözüm
Anahtar Kavram
Distance traveled during inattention and the multi-dimensional classification of mobile device distractions
Tahmini Süre:1m 30s