what comes next has to be about the 2 "hostages". It can't be about the traffic that is holding them hostage. If this sentence was handed to any English teacher, they would immediate get their red pens out and write "This is a misplaced participial phrase"
It's sort of like the example my English gave us when I was in high school. She said, "Running up a tree, I saw a squirrel." Then she asked us to write what thought was running up the tree. She got some pretty interesting answers.
The setting of a story help the reader better understand the character's personality by showing and giving details of what the character does in the setting.