It's not often that one gets a new web resource that isn't annoyingly flawed (yeah you Open Railway Map) or compromised by enshitification (like Gas Buddy). I might be late to the party on this, but Defectdetector.net has somehow managed to document every railroad defect detector in North America and then provide the information via a clean Google Maps type interface. Not only do we have both large and small railroads included, each pinned location has the full set of details about the detector including make, model and, if available, a recording of the output.
Of course nothing is perfect so if I had to provide feedback I would recommend ways to map defunct detectors and historic recordings. I would also enable filtering based on detector details like type (HBD, DED, etc) and also collect data on the information contained in the radio readouts like axle count or temperature.
One specific usability issue is the SP/DRGW practice of equipping every automatic signal location with a physical impact stick style DED that is attached to the signal system, as opposed to a radio readout. This results in many Union Pacific routes having every ABS signal location pinned as a DED. While this can be helpful in some sense, it also clutters/slows the interactive map interface.
While this site represents an amazing resource, I worry it will not last as Google maps integration isn't free. Airraidsirens.net, which I assure you is a thing, makes use of a Google Maps layer that fully lives in the Google ecosystem.
