Trip Generation Example

Institute of Transportation Engineers (ITE) is the primary source of trip generation data in the Trip Generation Manual. Land use types include residential, lodging, recreational, institutional, medical, office, retail, and services. Process for estimating trips from the ITE Trip Generation Manual: -Choose the appropriate land use. Choose the appropriate analysis time period and independent variable. Estimates of exiting and entering trips are available through average rates or an equation - collecting data at a similar site is also an option. Selecting whether to use the equation or average rate is based on (also check that the value of the given independent variable is within the limits of the data): -Equation is preferred [use if R2 is less than 0.75]. If the equation is unsuitable, use the average rate [if the standard deviation is less than 55% of the average rate]. NOTE: This is a correction from the video: the 3rd Edition of the Trip Generation Handbook uses 55%, from Page 26: "The weighted standard deviation for the average rate is less than 55 percent of the weighted average rate." Example Problem: Estimate the trips generated by all vehicles at a gasoline station with 14 fueling positions and a convenience market and fast food restaurant during a weekday PM peak hour of the gasoline station. The independent variable is given as 14 fueling positions (which is within the limits of the data, which vary from 8 to 20 fueling positions as shown on the graph). The equation should not be used because the R2 is less than 0.75. The average rate can be used because the standard deviation is less than 1.1 times the average rate (1.1 times the standard deviation of 9.35 is 10.285, which is lower than the average rate of 21.78).