San Francisco's light rail to drop 3.5-inch floppy disks

Back in 1998, the San Francisco Municipal Transportation Agency started using a floppy-disk based control system. Since its first day of operation, this system required the daily update of 3.5-inch floppy disks. Although it worked fine until now, it was initially supposed to have an operating period of 20 to 25 years. Now in its 26th year, this system is exposed to an ever-increasing risk of data loss which would lead to a catastrophic failure sooner or later.

The first commercial floppy disks were developed almost six decades ago and were 8 inches in diameter. They became commercially available in 1971 and were followed by the 5.25-inch forma in 1976. In a decade, IBM moved to 3.5-inch floppy disks, introducing the 720 KB format in the Convertible laptop and the 1.44 MB version in the PS/2 line. Although the hardware is no completely obsolete for home use, the symbol is still used in many software interfaces for functions such as file saving. Windows 10 and Windows 11 no longer provide drivers for internal or external floppy drives, but a separate devices driver is still provided if needed. The Boeing 747-400 fleet belonging to British Airways used 3.5-inch floppies for its avionics software until 2020, when it was entirely retired.

Since the floppy disk-based system of the San Francisco light rail cannot be simply retired, it needs an upgrade that would reduce the chance for malfunction. For now, it looks like no quick upgrade solution is available and, the entire process could take around a decade. This involves funding the project alongside finding a contractor for this job that is expected to cost some hundred million.

As of April 2024, the Chuanganzhuo-branded 3.5-inch external USB-C floppy disk drive can be acquired for $26.99 off Amazon.