The one in nanuet? Lights been there for many years. I think people beep just for the echo. At least thats what I do occasionally 
I think its because its a one-lane tunnel for two-way traffic, and the traffic from one direction is coming right off a turn.
Legends vary as to the history of this enchanting location, but one thing is for sure: the millions of visitors who come from around the world to gain a firsthand experience of this phenomenon do not leave disappointed.