From the manual:
Traffic-Aware Cruise Control is
primarily intended for driving on dry, straight
roads, such as highways and freeways. It
should not be used on city streets.
Warning: Traffic-Aware Cruise Control
has limited deceleration ability and may
be unable to apply enough braking to
avoid a collision if a vehicle in front slows
suddenly, or if a vehicle enters your
driving lane in front of you. Never depend
on Traffic-Aware Cruise Control to slow
down the vehicle enough to prevent a
collision. Always keep your eyes on the
road when driving and be prepared to
take corrective action as needed.
Depending on Traffic-Aware Cruise
Control to slow the vehicle down enough
to prevent a collision can result in serious
injury or death.