Star Ford

Essays on lots of things since 1989.

The “Funnel of Elimination” in transit planning

on 2006 November 4

The “funnel of elimination” is the typical way for transportation planning projects to comply with NEPA‘s rule that “appropriate alternatives” be considered for projects of major scale. Below are some examples of the funnels. Basically, the governor, mayor, or whoever has planning authority picks their favorite system, and the consultants or agency is directed to create an analysis showing that the preferred system is the best. So they choose several alternatives that can’t win, and several measures that ensure that the alternatives can’t win, then they draw a funnel shaped graph to pretend that they have balanced everything and are operating in an open, scientific manner.

Here is one from Denver:

1. Initial Screening – A series of yes or no questions were used during initial screening to evaluate alignments, station locations, and technologies to each other within categories. Alternatives not eliminated in initial screening were then refined and evaluated in comparative screening.

2. Comparative Screening – Comparative screening continued to look at transit alignments and technologies relative to themselves within categories to determine if some were clearly better than others were. A qualitative (good/better/best) approach was used to determine the alternatives within each category that were more effective at meeting the purpose and need.

3. Detailed Screening – Alignments, station locations, and technologies remaining after comparative screening, were combined to create several different corridor-wide transit alternatives for analysis in detailed screening. A quantitative (measure-based) analysis was used to identify the strengths and weaknesses of the various alternatives.

4. Alternative Refinement – Alternatives that remained following detailed screening were developed in more detail and further analyzed as part of alternative refinement. The evaluation was more in depth than the detailed screening analysis and was used to determine the alternatives most responsive to the project purpose and need. This fourth level of screening considered engineering feasibility; potential effects on social, environmental, and economic resources; and an analysis of capital, operation, and maintenance costs.

Here is one for the Albuquerque-Santa Fe corridor:

What’s amusing about this one is that the Governor said he wanted to build commuter rail, and allocated money for it in 2003. Then they proceeded with this sham alternatives analysis. In order to ensure that the commuter rail would win, they used these measures, among a few others:

  • “Providing a cost-effective transportation alternative to general purpose lanes in the I-25 corridor”. Since the only other existing corridor is a rail corridor, then rail wins! Throwing “cost-effective” in there makes no difference in the outcome since there is only one possible choice in this “alternatives” analysis.
  • “Providing travel time reliability in the corridor.” There again, anything that has different speeds depending on the congestion level cannot win. Even if the rail alternatives was slower on average, using the phrase “tranvel time reliability” ensures that it wins!

Notably, really important measures as safety and cost are NOT included in the study!

Finally, here is one for the Goethals Bridge Modernization:


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