UPDATE - The executive director from ITE called me and then followed up with an email stating he believes I have violated their copyright by posting my analyses. My lawyer doesn't think so, but I'm not going to fund a Supreme Court case on blogging law. So I'm voluntarily taking down the spreadsheet. Feel free to email me at email@example.com if you want to chat about my analysis or if you need help with trip generation.
In any event, this has made me think a lot about ITE. I'm a loyal Fellow of the Instituite and a past president of the North Central section of ITE. ITE has played a huge role in my career. We've even contributed data at no charge to the Trip Generation Manual. I'll have a follow-up post before the end of the year with thoughts on possible reforms to ITE.
Here is a spreadsheet that compares the data in ITE's recently released 9th Edition of Trip Generation Manual versus the older 8th Edition - REMOVED.
Based on the analysis worksheet, I draw the following conclusions from the changes (outside of the new land use codes or new independent variables where no comparison can be drawn):
- Residential - Almost the same, with a very slight change downward
- Office - Almost the same
- Retail - Slight trend downward
- It turns out the trip generation rates/distribution percentages haven't changed for about two thirds of the overall data set (independent variable sheets of each land use code).
We've done our best with the data entry in the spreadsheet, but I definitely don't warrant it's accuracy/completeness and would love to hear back if you find any typos. We're putting this out there so you can compare the data yourselves and to crowd-source improving it.
Also, I'm fighting a cold and I'm not 100%. Let me know if you draw different conclusions.