Research suggests that the Trip Generation Manual—a familiar tool for planners calculating the vehicle trips expected to be generated by developments of various sizes and uses—produces "phantom trips" and unneeded automobile infrastructure.
Eric Jaffe suggests that it might time to add the Trip Generation Manual from the Institute for Transportation Engineers to the list of questionable planning tools. Jaffe cites research by Adam Millard-Bell of the University of California, Santa Cruz, "who challenges the merits of the Trip Generation Manual in an upcoming research paper [pdf] (nicely summarized in ACCESS magazine)." See the video below of Millard-Bell describing his research.
In the study, "Millard-Ball reports that the ITE manual may overestimate the number of trips generated from a new development by as much as 55 percent," according to Jaffe. The result of these "phantom trips": "cities may build way more roads than necessary, perpetuating sprawl and leaving less street space for non-drivers in the process."
FULL STORY: A Widely Used Planning Manual Tends to Recommend Building Far More Roads Than Necessary
Cities Have Doubled in Size Globally in the Last 20 Years, Study Says
New research from China finds an incredible rate of urban expansion in North America and China.
An Academic Debate With Very Real Consequences: Land Use Regulations and the Cost of Housing
An article from the journal Urban Studies is inspiring debate and controversy over a year after publication, presenting opposing opinions on fundamental questions about how land use regulation affects the housing market.
How Houston Achieved Lot Size Reform
Nolan Gray of George Mason University and Adam A. Millsap of the Charles Koch Institute write about a recent article they authored in the Journal of Planning Education and Research.
What ‘The Brutalist’ Teaches Us About Modern Cities
How architecture and urban landscapes reflect the trauma and dysfunction of the post-war experience.
‘Complete Streets’ Webpage Deleted in Federal Purge
Basic resources and information on building bike lanes and sidewalks, formerly housed on the government’s Complete Streets website, are now gone.
The VW Bus is Back — Now as an Electric Minivan
Volkswagen’s ID. Buzz reimagines its iconic Bus as a fully electric minivan, blending retro design with modern technology, a 231-mile range, and practical versatility to offer a stylish yet functional EV for the future.
Healing Through Parks: Altadena’s Path to Recovery After the Eaton Fire
In the wake of the Eaton Fire, Altadena is uniting to restore Loma Alta Park, creating a renewed space for recreation, community gathering, and resilience.
San Diego to Rescind Multi-Unit ADU Rule
The city wants to close a loophole that allowed developers to build apartment buildings on single-family lots as ADUs.
Electric Vehicles for All? Study Finds Disparities in Access and Incentives
A new UCLA study finds that while California has made progress in electric vehicle adoption, disadvantaged communities remain underserved in EV incentives, ownership, and charging access, requiring targeted policy changes to advance equity.
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.
City of Albany
UCLA Lewis Center for Regional Policy Studies
Mpact (formerly Rail~Volution)
Chaddick Institute at DePaul University
City of Piedmont, CA
Great Falls Development Authority, Inc.
HUDs Office of Policy Development and Research