Clue by Clue: The Switched Signs Solution
The man was tipped off that the gang was planning to kill him. He also knew that the gang would use on maps and street signs instead of GPS. Elm Street and Church Street are near each other and both are similar streets. The man hoped the killer would pay attention to the street signs over the map.
He was correct; the hit man went to 59 Elm Street because he thought it was 59 Church Street and killed the wrong person.