New way to gauge New York’s pulse

   The Port Authority of New York and New Jersey has begun publishing “PA Pulse,” monthly indexes of passenger and freight volumes. 
   The agency says while “the indices do not precisely account for every passenger or every dollar worth of freight that passes through port authority facilities, they approximate those quantities closely using observed data.” 
   The port authority said the indexes will track the rise and fall of regional transportation activity over time, controlling for predictable factors such as seasonal changes and calendar effects like the number of weekdays and weekend days in each month, moving holidays, and leap years.
   PA Freight Pulse combines four variables to measure goods movement:

• Air cargo tonnage at the port authority’s four commercial airports (LaGuardia, JFK International, Newark Liberty International, and Stewart International).
• Containerized cargo imports at regional port facilities (Port Elizabeth, Port Newark, Port Jersey, Howland Hook Marine Terminal, and the Brooklyn Waterfront).
• Containerized cargo exports at regional port facilities.
• Trucks on the six port authority bridges and tunnels (George Washington Bridge, Lincoln Tunnel, Holland Tunnel, Bayonne Bridge, Goethals Bridge, and Outerbridge Crossing). 

   For the most recent month, February, the freight index stands at 98.1, or 0.1 point lower than in January, and 3.1 points below where the index was in February 2011.
   Both the freight and the passenger components are indexed at 100, with the base year 2010.
   The passenger index is based on movements of air passengers at the agency’s airports; automobile occupants using the bridges and tunnels; and bus, ferry, light rail and railroad passengers.