Question

based on the kinematics data measured in distracted vs non - distracted driver videos, what is the most significant difference observed between a distracted driver and an undistracted driver?
the distracted driver has a significantly longer reaction distance due to a delayed response time.
the distracted driver has a shorter pre - obstacle distance because they were speeding.
the undistracted driver has a shorter total stopping distance because their vehicle is lighter.
the undistracted driver has a longer braking distance because they brake harder.

Explanation:

When a driver is distracted, they take longer to react (response time) compared to an undistracted driver. This delay in reaction time directly affects the pre - obstacle distance (the distance the vehicle travels before the driver starts braking). A distracted driver has a significantly longer reaction distance due to this delayed response time. Other options like braking harder (which would reduce stopping distance if true, but distracted drivers don't necessarily brake harder), vehicle weight (lighter vehicle is not the key difference here as the question is about distraction), and speeding (not indicated as the main factor related to distraction in this context) are less relevant.

Answer:

The distracted driver has a significantly longer reaction distance due to a delayed response time.