Highway Research Record, Numéro 88

adjustment factors analysis average trip length barrier calibration characteristics clustered sample clustered survey comparison curves determine developed Diff district-to-district dwelling unit employment equations estimated trip Figure forecast gravity model trip home interview survey hours of travel households increment indicated input interzonal land land-use length frequency distributions minimum path modal split procedure model theory nonwork trips number of trips O-D data O-D survey obtained parameters percent person hours population Potomac River prediction productions and attractions reduced sample regression regression analysis relationships residential RMS error screenline selected zones Sensitivity Test Sioux Falls socio-economic spatial separation Table tion total number total study area TOTAL TRIPS traffic assignment transit usage travel patterns travel time factors trip attractions trip data trip interchanges trip length frequency trip purpose trips crossing UNIVERSITY OF CALIFORNIA urban area variables vehicular trips volume group zero sector zonal trip production zone pair zone-to-zone