San Francisco's Transbay Transit Center is just the latest example of an urban mega-project experiencing an enormous cost overrun. Eric Jaffe examines what the causes of this all too common phenomenon might be.
"So how did it get to the point where the only thing we can confidently expect from a big infrastructure project is that it will cost way more than expected?"
"One thing's for sure: the people who predict the cost of urban mega-projects do a terrible job," writes Jaffe. "Several years ago the University of Oxford scholar Bent Flyvbjerg, who's made a career researching mega-project mismanagement, analyzed 258 transportation infrastructure projects from around the world and found that nine in ten exceeded their cost estimates. The overruns were greater on rail projects than road projects but averaged 28 percent across the board."
"Whatever the underlying causes of cost overruns may be, there seems to be one promising means of addressing them: creating a 'reference class' of similar projects to serve as a platform for comparing costs. The idea, as explained by [psychologist Daniel] Kahneman in 2003 [PDF], is that old outcomes can serve as a barometer for recognizing just how unrealistic a biased new prediction might be — and help adjust it accordingly. Such a strategy controls for both political chicanery and cognitive biases alike."
FULL STORY: Why Mega-Projects End Up Costing Way More Than Expected

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

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?

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.

San Diego Adopts First Mobility Master Plan
The plan provides a comprehensive framework for making San Diego’s transportation network more multimodal, accessible, and sustainable.

Housing, Supportive Service Providers Brace for Federal Cuts
Organizations that provide housing assistance are tightening their purse strings and making plans for maintaining operations if federal funding dries up.

Op-Ed: Why an Effective Passenger Rail Network Needs Government Involvement
An outdated rail network that privileges freight won’t be fixed by privatizing Amtrak.
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.
New York City School Construction Authority
Village of Glen Ellyn
Central Transportation Planning Staff/Boston Region MPO
Institute for Housing and Urban Development Studies (IHS)
City of Grandview
Harvard GSD Executive Education
Regional Transportation Commission of Southern Nevada
Toledo-Lucas County Plan Commissions