UPDATE 2 – We’ve decided to collect our own Trip Generation data and share it for free. You can download it here.
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 firstname.lastname@example.org 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.
I really appreciate your blog. What a great resource. Thank you!
Thank you for this spreadsheet, this is my first time using the trip generation manual i am a student at Ryerson University. I was wondering if you could explain what the columns labelled “weekday”, “am”, and “pm” represented.
Daily = vehicle trips per day generated.
AM = vehicle trips generated during the 60 busiest minutes during the morning peak period between 7-9 am.
PM = vehicle trips generated during the 60 busiest minutes during the evening
peak period between 4-6 pm.
Mike, I too am a loyal member of ITE but your call from the Executive Director about copyright violations is disturbing. Now we inhibit the furtherance of the profession by waving the copyright laws?
I am having a problem trying to equate a comparison of 8th Ed. numbers with 9th Ed. numbers as having anything whatsoever to do with copyright violations. In my 50+ years of practice I cannot count the number of times I have, in analyses, reports, presentations, etc., made comparisons or looked at differences in a number of professional publications as they change over the years.
In fact, several years ago, I authored the update to the Trip Generation Professional Development Modules for ITE and, subsequently, made a number of presentations to local ITE chapters, ACSE , and APWA to educate them on the updates and changes from the 7th Ed. to the 8th ed.
I would be most interested in knowing what rationale Tom used in claiming a “copyright violation.”
BTW, I believe your post on the ITE Community will stir some vigerous thought and comment and I applaud you for taking a forward-looking view.
Edward J. Kant, P.E.
Semi-retired and still practicing
(some day I’ll get it right…)
I’ve invited Tom to post his rationale on this blog. So maybe we’ll get more details.
I’m an urban planning grad student at UCLA doing transportation research. Strangely this ITE TG data is inaccessible (unless you’re fine with settling for versions from many years ago). Would you be willing to share a copy of the file?
Is it possible for you to email your excel spread sheet to me? I need it for comparing child care centre trip generation comparison in Australia.
Sorry – we can’t share it anymore.
I was interested in taking a look at your analysis, because I wanted to see if a single family home generated more trips per unit than a townhouse. The City where I work, does not own the ITE manual, and it was just a question that came up at a meeting. I said a single family house generated more trips (assuming most single family homes are in suburbs and townhouses are in mixed neighborhoods with more accessibility to alternate transportation options). As I think more about this, it would depend where the land use is located.
Aleida – Generally, a single family home generates about 10 trips per day (5 cars in + 5 cars out) and a townhome generates 6 cars per day. These are national averages. Of course it’s possible a specific townhome could generate more traffic than a specific single family home.
In reading the application for a motel that is expanding and adding 23 rooms, the Engineer claims that “Per the ITE Generation Manual –9th Edition” it is now classified as a Hotel. It has been a motel for 40 years, and is expaning, and claiming it is a Hotel, so according the the 9th edition, a traffic study is not required. What are the code differences between a hotel and a motel.
The owner wants to add 23 new rooms in a new building on the grounds of the existing 2 story motel building. The entrance/exit to the motel converges with a major restaurant located across the street,and a popular bank into a one-way bridge. Its risky at that exit now – with 23 more rooms even riskier. Where could I get more documents to study the traffic flow? Are the stats different in the 9th Edition vs the 8th Edition of the manual? Thanks for your help.
Having been retired from an environmental engineering firm 4 years, I don’t have convenience of colleagues to discuss the ITE classification 251 (senior living community). I can’t afford to purchase the ITE 9th edition but would appreciate at least a classification definition and the potential AM and PM maximum daily traffic impact for a 55+ community of 500 DU. I know it’s based on a regression analysis which indicates a 0.27 value during peak conditions. However I find this value low given the number of people at their peak earning years and not wanting to “retire” at 55 (therefore not going to work at peak hours).
Thanks for clarifying the Trip Generation Manual’s position on this question, for those of us who do not own the Trip Generation Manual! I happen to be googling material related to Aleida’s question because my home town is considering an application for a 92-unit rowhouse development, all of whose residents will need to come and go via a small local street that forms a T-intersection (with a stop sign) with a fairly busy collector street, about 1000 feet or so from where that collector street has a major intersection with a regional highway. This is a suburban location, almost no mass transit availability. Houses will be 3 bedroom/1500 square feet/attached 2-car garage. And the planners want us to believe that the trip generation rate will only be about 60% of what it would be for detached single-family homes. I really do not see any justification for making such an assumption. (After all, people do not base their travel choices on whether or not they have a large front yard, or whether their house is joined to their neighbor’s house.) I think the likely explanation is that the Trip Generation Manual’s data for the “townhouse” land use category probably includes quite a lot of studies from developments where either mass transit was available/used, or else, where a large percentage of the occupants were retired or semi-retired. Unfortunately, it may be an uphill fight to get the planners to re-evaluate the trip generation assumptions for this project …
Mike – I dealt with them very recently, regarding their data. Feel free to email me your phone number and I’ll describe the exchange I had with them – it should provide some perspective for you to keep in mind in the future.
I’d like to know the correct “Trips Per Unit” for Code 560 (Church) as shown in the ITE Ninth or Tenth Additions. The spread sheet in my possession shows 0.55/1000sf for the 9TH.
For a 21,600 sf church, that only calculates to be 11.88 PHT.
I came across you website and I am hoping you can help me. I am a pastor of a small church on the edge of our town. The municipality is preparing for street project. Part of our assessment is based on frontage – I get that & the math is easy. Another portion is based on “trips”. We are assessed an average daily trip number of 205.86. Based on actual attendance numbers, our very high side estimate is 40 trips per day. When questioned, they quoted the ITE Trip Generation Manual, which says the calculation is “36.63 per 1000 sq ft of gross floor area ON A SUNDAY”. I dont know what “on a sunday” has to do with this since it is all based on trips per sq ft. We do happen to have about 75 people on a sunday, which would be around 36 trips, but the volume is near zero the rest of the week – so stretching it to 205/day is way beyond reasonable. $6000 is on the line, so I felt it was worth doing a little research. Any insight you can provide would be greatly appreciated.
Thank you, Pastor Wade
Hi Pastor Wade – A more appropriate measure of trip generation for churches is to do it per seat as different sanctuaries have much different densities of seating. Also, we’d need to see what the city’s policy is to see if you have wiggle room to argue weekday vs. Sunday. Feel free to email me at email@example.com with the number of seats in the sanctuary and the city’s policy. Then I can get you a more solid evaluation. Mike
With reference to my earlier question, I’d like to request the “Peak Hour Trip Rate”
(per 1000 sf) from the “Institute of Transportation Engineers” 9th and/or 10th Editions for a Church (I.T.E. Code 560)
Thank you for your analysis!
I’m with your lawyer.
ı studied on trip generation and ı need a calculation parts of the trip generation and methodology please help me
You’ll need to go to ITE and purchase their document, take their courses.