Travel Demand Forecasting: Trip Generation CE331 Transportation Engineering

Land Use and Socio- economic Projections Trip Generation Trip Distribution Modal Split Traffic Assignment Transportation System Specifications Direct User Impacts Overall Procedure

Trip Generation Relate Trip-making intensity to and from specific land-use parcels (trips generated, trip rate, …) to The measures of the type and intensity of land use on those parcels (population, employment, income, …)

How Many Trips? Product: Trip productions and attractions for each zone Trip Purposes HBW – Home based work trip HBNW – Home based non-work trip NHB – Non-home based trip Usually computed using trip generation rates

Example 1 Shopping trips per day T i = HH i –0.1 EMP i INC i Zone A: Avg. household size (HH) 2.5 persons Avg. income (INC) 50 ($50,000) Employees per household 1.5 Trips: T A = (2.5)-0.1(1.5)+0.01(50) = 0.95

Example 2 Shopping trips per day T i = HH i +0.1 EMP i INC i HH EMP INC T i Zone A30% % % Total trips =.3(2.81) +.6(2.43)+.1(2.19) = 2.52 trips

How to Develop the Equation? Regression Least Squares Method Find relationship between variables based on empirical data (curve fitting)

Example 3

Example 3 (cont’d) Y = X