Driver 1 was in the center lane of a three- lane road traveling 20 miles per hour
(30 km/h). She was watching two drivers
in the far-right lane who were arguing
over a fender bender. Without realizing
it, Driver 1 drifted left into the far-left
lane, causing Driver 2, who was traveling
at 35 miles per hour (55 km/h), to
abruptly hit his brakes. Driver 2 was not
able to stop in time to avoid clipping the
side of Driver 1's car. Who's at fault?