I'm not sure specifically as there could be many novels named in such a way. It might be about the breakdown of a relationship, a society, or a character's mental state.
The breakdown of a romance novel could be due to various factors. For example, the lack of chemistry between the main characters. If the hero and heroine don't have that spark, it can make the whole story fall flat. Also, a weak plot can contribute to it. If the story just follows a predictable pattern without any twists or turns, readers may lose interest.
Definitely not. 'Breakdown lane' is a traffic-related term and has nothing to do with being a fictional book. It's an area on a highway for vehicles that have broken down.
One scary car breakdown story I heard was when a person was driving alone at night on a deserted highway. Suddenly, the engine just cut out and all the lights went off. They were in the middle of nowhere with no cell phone signal. It was pitch black and every little noise made them jump. They had to wait for hours until a passing truck finally stopped to help.