One day when Lucy was walking to the park she received a call that a close family member had passed. She suddenly felt flustered and no longer had control of her emotions.
Freuds theory of Dreams states that dreams censor our unconscious desires to protect us. This is done using symbols that reflect our unconscious thoughts. Lucy's dream getting into the car accident and not being able to stop it symbolizes her losing control and being at a roadblock.
When she goes to bed that night and has a dream that she somehow appears in her car, and collides with another car and she is unable to stop it. Just after she collides with another car she wakes up in a panic.