Freeport new york MTA railroad station signal bridge

On the platform at the MTA railroad station in freeport nassau county new york
In the video you will see the signal bridge in the track area
Signal bridges are more or less the equivalent of traffic signal lights on roadways
They let the train operators know things like if there is a train ahead or to change the speed of the train depending on the position of the signal lights
At the end of the video you will hear a m3 train passing thru and it's horn