Recent studies indicate that current planning practices require economically-excessive road and parking supply. This research provides practical guidance to help communities devote less land to vehicles and more land to people.
Two recent studies provide further evidence that current planning practices require economically-excessive road and parking supply, a problem that becomes more severe as vehicle travel peaks and demand for alternative modes and more multi-modal communities increases.
Phantom Trips: Overestimating the Traffic Impacts of New Development by Professor Adam Millard-Ball critically examined the methods commonly used to predict trip generation, that is, the additional vehicle traffic resulting from new development. The study found that commonly used methods, such as the ITE Trip Generation Manual:
• Overestimate trip generation in smart growth locations.
• Use biased samples, since surveys are generally performed at “successful” sites.
• Assume that any trips made from a new building are “new” trips, rather than shifts of existing regional trips that would occur if the building had not been constructed.
As a result of these factors the author concludes that current practices greatly overestimate the number of vehicle trips that can be attributed to any development project, resulting in economically-excessive urban roadway capacity and a structural bias against infill development.
Trip Generation for Smart Growth Projects by Robert J. Schneider, Susan L. Handy and Kevan Shafizadeh applied a new, more rigorous data collection method to count vehicle trips at urban sites. The results indicate that commonly-used trip generation prediction models significantly overestimate trip generation in smart growth locations, by an average of 2.3 times at the sites studied. The results were used to develop the Smart Growth Trip-Generation Adjustment Tool which can be used to adjust available trip-generation rates for smart growth development projects. Most of these findings are transferable to parking generation analysis.
These studies provide further evidence that smart growth development can provide large savings and benefits, including savings to households (from reduced vehicle expenses), developers (from less parking and transportation impact costs) and governments (from reduced roadway costs), and that current planning practices are significantly biased in favor of sprawl and automobile-dependency. These studies provide practical guidance to help communities devote less land to vehicles and more land to people.
FULL STORY: Access Magazine
Alabama: Trump Terminates Settlements for Black Communities Harmed By Raw Sewage
Trump deemed the landmark civil rights agreement “illegal DEI and environmental justice policy.”
Planetizen Federal Action Tracker
A weekly monitor of how Trump’s orders and actions are impacting planners and planning in America.
The 120 Year Old Tiny Home Villages That Sheltered San Francisco’s Earthquake Refugees
More than a century ago, San Francisco mobilized to house thousands of residents displaced by the 1906 earthquake. Could their strategy offer a model for the present?
In Both Crashes and Crime, Public Transportation is Far Safer than Driving
Contrary to popular assumptions, public transportation has far lower crash and crime rates than automobile travel. For safer communities, improve and encourage transit travel.
Report: Zoning Reforms Should Complement Nashville’s Ambitious Transit Plan
Without reform, restrictive zoning codes will limit the impact of the city’s planned transit expansion and could exclude some of the residents who depend on transit the most.
Judge Orders Release of Frozen IRA, IIJA Funding
The decision is a victory for environmental groups who charged that freezing funds for critical infrastructure and disaster response programs caused “real and irreparable harm” to communities.
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.
Clanton & Associates, Inc.
Jessamine County Fiscal Court
Institute for Housing and Urban Development Studies (IHS)
City of Grandview
Harvard GSD Executive Education
Toledo-Lucas County Plan Commissions
Salt Lake City
NYU Wagner Graduate School of Public Service