On Sunday, November 15, 2015 at 11:54:30 AM UTC-5, houn...@yahoo.co.uk wrote:   
      
   > They've introduced moving block on the Canarsie line, with go-no-go   
   > waysides only at danger points. There are plans to do same on the   
   > Flushing Line as newer trains already have auto-pilot, though they are   
   > not yet operating in that mode.   
      
   > It will nonetheless be a while before they manage to modernise   
   > signalling on a behemoth like the New York City Subway. I mean, OPTO is   
   > only relatively a new phenomenon.   
      
   What one of the challenges of the NYC subway infrastructure is that it's   
   so huge and coplex.  Going to an entirely new technology of signals   
   requires a massive conversion of both wayside and rolling stock that is   
   in heavy use every day.   
      
   The Flushing and Canarsie lines were converted first because they   
   are isolated.  Other lines are shared and more complex.   
      
   Another challenge is safety.  It was discovered that some signals   
   did not offer adequate protection, that is, if a motorman ran them,   
   the emergency brakes would not stop the train in time.  So, signal   
   spacing was increased which reduced capacity.  Likewise with speed   
   controls.   
      
   A similar program is underway on Metro North after some accidents.   
   Unfortunately, it means increased run times.   
      
   Naturally, as a passenger I want to be safe.  But sometimes I wonder,   
   when the overall history is considered, if some signal safety efforts   
   go too far, perhaps ordered by remote bureaucrats or politicians.   
   I'm not in a position to know the real facts.  But if trains run too   
   slow, passengers will abandon them for their private automobile,   
   which is far more dangerous.   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)