Shoup Critique Of ITE Parking, Traffic Generation Manuals

Long the bible for planners, the ITE standards are misleading and reinforce car dependence

1 minute read

July 31, 2002, 2:00 PM PDT

By Abhijeet Chavan @http://twitter.com/legalaidtech


In a more popular version of a forthcoming article in the Journal of Transportation and Statistics, Donald Shoup chronicles the problems with the ITE Parking Generation and Trip generation manuals that have become standards for planners and transport professionals in the U.S. and even abroad. He demonstrates that their ostensible accuracy is unmerited and misleading; that average rates are most often presented despite lack of statistical evidence for any relation between floor area and trips generated; and, more profoundly, that the tables are based on assumptions of car dependent land use that the manuals help become self-fulfilling, as follows. Rates are derived from studies of peak parking demand and number of trips in suburban sites with ample free parking--lacking transit, pedestrian facilities, or TDM; these are then used to mandate the design of new developments, thus ensuring that parking in these will be free, and densities low (so traffic generated at the predicted rates does not overwhelm roads.) When such sites are surveyed in the future, they will, indeed, validate these rates. Voila!

Thanks to Yaakov J. Garb, ITDP

Wednesday, July 31, 2002 in University Of California Transportation Center

portrait of professional woman

I love the variety of courses, many practical, and all richly illustrated. They have inspired many ideas that I've applied in practice, and in my own teaching. Mary G., Urban Planner

I love the variety of courses, many practical, and all richly illustrated. They have inspired many ideas that I've applied in practice, and in my own teaching.

Mary G., Urban Planner

Get top-rated, practical training

Logo for Planetizen Federal Action Tracker with black and white image of U.S. Capitol with water ripple overlay.

Planetizen Federal Action Tracker

A weekly monitor of how Trump’s orders and actions are impacting planners and planning in America.

April 30, 2025 - Diana Ionescu

Close-up on Canadian flag with Canada Parliament building blurred in background.

Canada vs. Kamala: Whose Liberal Housing Platform Comes Out on Top?

As Canada votes for a new Prime Minister, what can America learn from the leading liberal candidate of its neighbor to the north?

April 28, 2025 - Benjamin Schneider

Hot air balloons rise over Downtown Boise with the State Capitol building visible amidst the high rises.

The Five Most-Changed American Cities

A ranking of population change, home values, and jobs highlights the nation’s most dynamic and most stagnant regions.

April 23, 2025 - GoodMigrations

A large Google data center building in the Netherlands.

Rethinking Computing: Researchers Tackle AI’s Energy Demands

USC researchers are reimagining how AI systems are trained and powered — through smarter algorithms, innovative hardware, and brain-inspired designs — to dramatically reduce computing’s energy footprint.

May 4 - USC News

Close-up of smartphone with Zoox logo and screen with blurred image of Zoox autonomous vehicle in background.

Amazon-Owned Robotaxis to Begin Testing in LA

Los Angeles will become the sixth city where Zoox is testing its autonomous vehicle technology.

May 4 - Smart Cities Dive

NYC MTA train on elevated rail with Manhattan skyline visible in background.

New York MTA Says No More Borrowing, Will Cut Costs Instead

The agency says it won’t take out any new loans to finance its planned improvements and is finding other ways to cut costs.

May 4 - Bloomberg CityLab

Urban Design for Planners 1: Software Tools

This six-course series explores essential urban design concepts using open source software and equips planners with the tools they need to participate fully in the urban design process.

Planning for Universal Design

Learn the tools for implementing Universal Design in planning regulations.

Senior Manager Operations, Urban Planning

New York City School Construction Authority

Building Inspector

Village of Glen Ellyn

Manager of Model Development

Central Transportation Planning Staff/Boston Region MPO