I just saw it a few days ago.
Basically Henry (the suicidal guy) was driving on the bridge, the tire blew, his whole family was killed, he was also dying.
But just before he died, his mind was making up some dreams/delusion from the people he could see around him. Basically the whole story/film was just his delusion before his death.
The last part of the movie on the bridge was quite straightforward about this, all the characters in his dreams were the bystanders who were trying to save him.
It's a little frustrating since basically the end of the movie tells you that everything you just saw was just dreams/delusion and basically nothing happened except a fatal car accident.
I liked the movie's aesthetics, but that's about it.