Passengers per hour per direction (p/h/d),United Kingdom Parliament, Integrated Transport: The Future of Light Rail and Modern Trams in Britain Inquiry, Memorandum by Transport for London , 2005-08-10. passengers per hour in peak directionU.S. Department of Transportation, Report on South American Bus Rapid Transit Field Visits: Tracking the Evolution of the TransMilenio Model , 2007-12, retrieved 2008-07-10.