Sentence 1: Susie was stuck in traffic for a long time. 
 Sentence 3: Finally she saw there was a car accident 
 Sentence 4:  That explained why the traffic was so heavy 
 Sentence 5:  Once Susie bypassed it, she was in her way 
 Option 1: She was on highway and was a part of a accident. 
 Option 2: She was on the highway and getting kind of irritated.