The San Francisco Municipal Transportation Agency, which operates the city's light rail system, claims to be the first U.S. transit agency to adopt floppy disks. But today, SFMTA wants to abandon its reliance on 5 1/4-inch floppy disks. Give us six more years and hundreds of millions of dollars.
SFMTA members recently ABC7 Bay Area News He detailed that the agency uses three 51/4-inch floppy disks each morning. The floppy has been part of Muni Metro's Automatic Train Control System (ATCS) since it was installed at the Market Street subway station in 1998. The ATCS has multiple components, including “the propulsion and braking systems, a central control system, and computers in the train tied to the braking systems, local servers, and communication infrastructure such as looped cable signal lines.” SFMTA spokesperson Michael Roccaforte told Ars Technica.
Roccaforte said the floppy disks are for loading the software that runs the central server.
Rocaforte said initial planning for an overhaul of ATCS, including a transition from floppy disks, began in 2018 and was expected to take 10 years from initial planning to completion. Due to an 18-month shutdown related to COVID-19, completion is expected to take place between 2029 and 2030. SFMTA plans to select a contractor by early 2025 and will announce a detailed project schedule at that time.
“Ultimately, our goal is to implement a single train control system for the entire rail system,” said Jeffrey Tumlin, SFMTA transportation director. ABC7.
floppy defect
Some people say, “If it ain't broke, don't fix it.” But while train control systems that rely on floppy disks remain functional, relying on outdated technology has challenges that SFMTA has emphasized for years.
The transit agency has said the train control system has a useful lifespan of only 20 to 25 years, meaning it has exceeded its expected lifespan in 2023. In 2020, the Muni Reliability Working Group, made up of local and national transportation experts, recommended replacing them. The traffic control system will be completed within five to seven years.
When asked how “disastrous” it was to upgrade from a floppy disk, Tumlin said: ABC7 Everything is a risk.
“While the system is currently working well, we know that each year the risk of data degradation on the floppy disks increases and that at some point a catastrophic failure will occur,” Tumlin said. ABC7.
The Department of Transportation previously argued that maintaining ATCS would become more difficult and expensive over time. They also discussed the challenges of finding workers who know how to use outdated systems.
“To keep our current system working, we have to retain programmers who are experts in programming languages from the '90s, so we have decades of technical debt,” Tumlin said in 2023. Speaking on KQED in San Francisco in May.
