Train horns are required to be sounded by the railroad when approaching a highway-railroad grade crossings. A Federal Railroad Administration rule (49 CFR Parts 222 and 229) guides when and how train horns are to be sounded at crossings.
Included in the rule are ways in which communities can make safety improvements to silence the horns through the establishment of a quiet zone. The Federal Railroad Administration's Web site includes additional guidance on creating a quiet zone.
The Office of Rail Transportation has compiled a list of the appropriate railroad contacts for quiet zone issues in Iowa.