1. Travel Demand Forecasting: Trip Generation CE331 Transportation Engineering

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

3. 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, …)

4. 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

5. Example 1 Shopping trips per day T i = 0.10 + 0.2 HH i –0.1 EMP i + 0.01 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 = 0.10 +0.2(2.5)-0.1(1.5)+0.01(50) = 0.95

6. Example 2 Shopping trips per day T i = 0.15 + 0.4 HH i +0.1 EMP i + 0.02 INC i HH EMP INC T i Zone A30% 2.5 1.6 752.81 60% 2.0 1.8 652.43 10% 1.8 1.2 602.19 Total trips =.3(2.81) +.6(2.43)+.1(2.19) = 2.52 trips

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

8. Example 3

9. Example 3 (cont’d) Y = 0.333 + 0.699 X