TRIP GENERATION UPDATE

THIS REPORT IS THE THIRD IN THE SERIES OF MAJOR UPDATE REPORTS AND DEALS EXCLUSIVELY WITH THE TRIP GENERATION PHASE OF THE UPDATE. THE SCOPE OF THIS WORK INCLUDES THE GENERATION OF PRODUCTION AND ATTRACTION TRIP ENDS FOR NINE TRIP PURPOSES FOR THE TARGET YEARS OF 1975 AND 1990. THERE ARE A TOTAL OF NINE TRIP PURPOSES, FOR EACH OF WHICH A TRIP GENERATION WAS DONE SEPARATELY IN THIS UPDATE. THESE NINE PURPOSES INCLUDE SEVEN TRIP PURPOSES DEVELOPED BY THE PUGET SOUND REGIONAL TRANSPORTATION STUDY (PSRTS). TWO OF THE TRIP PURPOSES DEVELOPED BY PSRTS HAVE BEEN BROKEN DOWN INTO TWO PURPOSES EACH, TO REPRESENT MORE ADEQUATELY DIFFERENT TRIP-MAKING CHARACTERISTICS OF THESE TRIP PURPOSES. THESE PURPOSES ARE SHOPPING TRIPS, WHICH ARE NOW BROKEN DOWN INTO HOMEBASED SHOP CONVENIENCE TRIPS, AND HOME-BASED SHOP GAF (GENERAL MERCHANDISE, APPAREL AND FURNISHING) TRIPS; AND SCHOOL TRIPS. THE FOUR TYPES OF TRIPS FORECASTED WERE: INTERNAL TRIPS -- TRIPS WHICH HAVE BOTH PRODUCTION AND ATTRACTION ENDS WITHIN THE STUDY AREA; INTERNAL-EXTERNAL TRIPS -- WHICH HAVE ONE TRIP END WITHIN THE STUDY AREA AND THE OTHER OUTSIDE IT; THROUGH TRIPS -- WHICH HAVE BOTH THE TRIP ENDS OUTSIDE THE STUDY AREA; AND CROSS-SOUND TRIPS, WHICH ARE TRIPS CROSSING PUGET SOUND BY FERRY OR THE TACOMA NARROWS BRIDGE CONNECTING THE STUDY AREA EAST OF THE SOUND (MAINLAND) WITH THE AREA WEST OF THE SOUND (KITSAP). THE PROCEDURE USED FOR GENERATING FUTURE PRODUCTION AND ATTRACTION TRIP ENDS IS MAINLY CROSS CLASSIFICATION WHICH WAS DEVELOPED AND USED BY PSRTS. THIS METHOD RELATES TRIP MAKING TO SOCIO-ECONOMIC, LAND USE AND EMPLOYMENT CHARACTERISTICS OF EACH AREAL UNIT COMMONLY KNOWN AS A ZONE. TRIPS FOR EIGHT OF THE NINE PURPOSES WERE FORECASTED IN THIS MANNER, WHILE FOR ONE PURPOSE, WHICH IS NON-HOME BASED, A MULTIPLE REGRESSION EQUATION HAS BEEN USED WITH HOME-BASED TRIP ENDS AS ONE OF THE INDEPENDENT VARIABLES.