The Federal Railroad Administration (FRA), in cooperation with Union Pacific Railroad (UPR) and others, are responsible for the development and implementation of safety regulations in regard to train horns.
Most of the railroad crossings in Sahuarita are “at-grade crossings,” also known as "road-level crossings." This is where railroads cross roadways at the same level as roadway traffic. At these crossings, traffic must be stopped while a train moves through. To assure safety, federal regulations require that train horns be sounded for 15-20 seconds before reaching all road-level crossings, but not more than one-quarter mile in advance.
The FRA has defined a required pattern for blowing the horns: two long, one short, and one long-sounding horn. These are repeated as necessary until a train clears a crossing. Locomotive engineers are allowed to vary this pattern at crossings in close proximity to each other, and are also allowed to sound the horn in emergency situations.
In October 1996, federal regulations established an option for “quiet zones” at road-level crossings provided that safety measures are in place. Such "quiet zones" must also have an accident rate that meets federally acceptable standards.
UPR believes quiet zones compromise safety, and while they don’t endorse them, they do comply with these provisions of federal law. There are several types of “quiet zones” that a town could conceivably implement, but they all require meeting qualifying conditions, and include the installation of expensive gates, medians, fencing and warning equipment.
Estimated costs can be as high as $500,000 per crossing, with a connection fee of $5,000 to $15,000, and annual maintenance costs of $4,000 to $10,000. In order to silence the train horns in the Sahuarita area, these would have to be installed at every crossing, because horns can be heard from such great distance.