THE MATHEMATICAL FORM OF TRAVEL TIME FACTORS

Abstract

THE TRAVEL TIME FACTOR REPRESENTS THE EFFECT OF TRAVEL TIME ON TRIP INTERCHANGES. IN ITS USE IN GRAVITY MODEL STUDIES, THE TRAVEL TIME FACTOR IS AN EMPIRICAL HAND-DOWN CURVE THAT IS CONSIDERED CONSTANT OVER TIME. THIS PAPER QUESTIONS CONSTANCY OVER TIME BY ATTEMPTING TO EXPRESS TRAVEL TIME CURVES IN PARAMETRIC FORM AND RELATING THE PARAMETERS TO VARIABLES WITHIN THE STUDY AREA THAT ARE KNOWN TO CHANGE OVER TIME. DRIVING TIME CURVES FOR THREE TRIP PURPOSES WERE SELECTED FROM TEN WIDELY SCATTERED TRANSPORTATION STUDY AREAS OF DIFFERENT SIZES. BY CURVE MOMENT TECHNIQUES, THE TRAVEL TIME FACTORS WERE CLOSELY MODELED BY PEARSON TYPE I AND PEARSON TYPE III CURVES. THE TRAVEL TIME CURVES OF HOME-BASED WORK AND NON-HOME-BASED TRIPS WERE BEST MODELED BY PEARSON I CURVES, WHEREAS THE FACTORS FOR SHORTER LENGTH SHOPPING TRIPS WERE BETTER MODELED BY PEARSON III CURVES. USING FACTOR ANALYSIS AND CORRELATION ANALYSIS FOR THE SELECTION OF INDEPENDENT VARIABLES, REGRESSION EQUATIONS OF ACCEPTABLE STATISTICAL SIGNIFICANCE WERE DERIVED RELATING THE PARAMETERS OF THE PEARSON MODELS TO VARIABLES CALCULATED ON A CITYWIDE BASES. THE STUDY FOUND SIGNIFICANT RELATIONS BETWEEN CURVE PARAMETERS AND SUCH EPHEMERAL VARIABLES AS NUMBERS OF TRIPS MADE, TRIP-MAKING RATES, CAR OWNERSHIP, AND RATIOS OF TRIPS MADE FOR VARIOUS PURPOSES. /AUTHOR/

Cite this work

No public copy is stored for this record, so only the metadata is cited.

Stored only when both papers are in the corpus — 5 citations exist upstream.