: The equipment on the train is generally a flat rate package of electronics costing ~$50,000 (possibly double if that is per cab).  The majority of the expense is getting it installed in the signaling system.  In addition to hardware that has to be installed at every existing signaling location you need to install reliable data radios at every interlocking that are tied in to a central management system.  All of that then has to be rigorously tested which can take months and cost even more money.  Another huge hangup for Amtrak is that SEPTA and other railroads that use the NEC are not ACSES equipped and Amtrak can't deploy the system until they are.  For SEPTA that would involve equipping 400 some odd railcars @ $50,000 (or more) each ($20 million total).  SEPTA is currently broke and shutting down a major commuter rail operation is generally considered a non-starter.  Finally PTC has a number of big operational problems that Amtrak has gone out of its way to avoid.  It slows trains down beyond what is safe, it makes it difficult to perform station stops under certain conditions and reduces capacity in a number of other ways.  When the system fails it creates additional headaches and the more places it is installed the more things will go wrong.  Check out the ACSES page for specifics. Long story short accidents such as this are rare events and the hassle of trying to prevent them gums up railroad operations.