Generally, all 'train control' systems take a long time to roll out. Despite often seeming like one product you 'install' from one vendor, it's really more of a

Generally, all 'train control' systems take a long time to roll out. Despite often seeming like one product you 'install' from one vendor, it's really more of a 'solution' that requires a bunch of things you deploy together, and parts of it are delivered by subcontractors. For the relatively simple system that the NYC began using -- Siemens Trainguard MT, used in some other cities, and also on PATH -- you need trackside beacons, lots of wiring (and a good amount of wireless), in-car computing units in the IT closet, in-cab signalling, on-car sensors, in-car wiring, etc [1], a bunch of IT integration and troubleshooting; not to mention "soft deliverables" like conductor training, maintenance training, dispatcher training, safety and bureaucratic approvals, and lots of testing. Even if you assume that all parties are competent and are acting in good faith, this still takes time. In a recent thread about the Amtrak Cascades derailment [2], a conversation about (positive) train control ensued, and some people who worked on such implementations also talked about why these projects tend to be complex. [1] http://www.mobility.siemens.com/mobility/global/SiteCollectionDocuments/en/rail-solutions/rail-automation/train-control-systems/trainguard-mt-en.pdf http://www.mobility.siemens.com/mobility/global/SiteCollecti... [2] https://news.ycombinator.com/item?id=15968720 https://news.ycombinator.com/item?id=15968720