If I remember correctly, legislation was passed in 2007 requiring trains everywhere in the US to blast their horn four times (length unspecified) before every crossing. The only exceptions are quad-gated crossing (I believe that means a gate covering each lane of traffic on both sides) or in specified "quiet zones".

In my area, the trains only get active at around 11:30pm, an continue their racket through the entire night. I'm regularly awakened by needlessly long honking around 4am. It's awful.