Did you know that trains have their own language? I didn’t, either. After trains began sounding their horns in downtown San Diego again recently, I started investigating. Most of downtown lies within a designated train “quiet zone” — meaning the frequent railroad crossings often don’t include the typical whistle. What railway officials call trains “blowing their whistles” really sounds more like an annoyingly ear-piercing horn blast to most. That’s why the city made a $21 million investment in 2010 into extensive safety improvements that include a sophisticated warning system — all so that trains would no longer have to sound their horns for 15-20 seconds as they approach. Earlier this year, the city’s quiet zone was suspended when a Federal Railroad Administration inspection found safety violations that needed to be fixed. Downtown residents accustomed to being spared such blasts were in an uproar, so the city expedited repairs to get the designation restored in weeks. But more recently, trains have been heard sounding their horns again at various intersections. To someone rudely awakened from sleep, there might seem to be no rhyme or reason to the choo choos — but certain patterns of horn blasts are used to alert people to different obstructions. A full sequence — two long, one short and one long blast — is a train’s standardized pattern to alert a crossing. Those are the ones typically silenced in quiet zones. But if the train blows just a few blasts, they’re intended to warn a trespasser, roadway workers or signal maintainers on or near the tracks. Ultimately, trains can sound their horns whenever their operators feel like it — even in a quiet zone. FRA train rules allow operators — technically called locomotive engineers — to sound the horn in a quiet zone if they feel that a crossing is unsafe, if they see trespassers around the track or if there are any mechanical issues with the warning devices. Unfortunately, any one of these conditions almost always applies downtown, whether because of pedestrians or homeless people frequently crossing the tracks or ongoing construction. North County Transit District officials agree. “The prevalence of trespassers in the railroad right-of-way in the downtown San Diego area presents a significant safety concern, and therefore, train horns must be applied in order to comply with the regulations and endeavor to keep people safe,” one official said. BNSF Freight officials also noted that construction work that has been underway at Broadway, just south of the San Diego Depot, in recent weeks has required trains to sound their horns in the area — even if workers may not always be seen at the exact crossing. Residents can report any alleged violations online, but it looks like the train horns are, at least in part, here to stay.