Linklist: March 14, 2012

Brendon Slotterback on David Alpert on driverless cars:

“I’ve been meaning to write a “how this urbanist stopped worrying and learned to love the driverless car” post for a while, but I’ve finally been spurred into action by this piece in the Atlantic Cities by Greater Greater Washington founder David Alpert. Right up front I want to say I still have a lot of concerns about how we plan and incorporate robot cars, but on this issue of competing road users, I take a different view.”


Jarret Walker: quote of the week: hopeful intentions of the u.s. federal transit administration:

“[In reading this, recall that mobility means “how far you can go” or “how much area you can cover” in a given time.  “Accessibility” or “access” means “how many economic, social, and recreational opportunites that you can reach” in a given time.]

“[The U.S. Federal Transit Administration (FTA)] believes improvements to both access and mobility are key features of a good transit investment. FTA agrees a measure that defines accessibility instead of mobility might be a better representation of the kind of benefits transit projects are intended to produce. As noted, however, it has proven very difficult to measure. Although it is relatively easy to specify a measure such as number of jobs within a specified travel time of a single location, creating a broader corridor or regional measure including calculations to and from multiple locations is more difficult and complex. FTA believes a measure focusing on project ridership will indirectly address access improvements since more people will ride a project that has enhanced access to jobs or other important activity centers. Focusing on the way a transit project can enhance an individual’s ability to get places, rather than just travel faster, is a desirable outcome of the evaluation process. FTA intends to continue to explore how best to do so.”

The FTA’s Notice of Proposed Rule Making [pdf] that 
proposes to shift the criteria for funding 
new transit projects from travel time to ridership, 
a move that Socrates* had some questions about.
Hat tip to Susan Pantell for reminding me
of this passage.

This is indeed hopeful.  I’ll lay out a fuller argument on how this agenda might move forward in a coming post.

Question: When FTA refers to the difficulty of aggregating accessibility measures for everyone in a region, do you think they’re referring to a logical problem (i.e. the stated task is logically or philophically incoherent), or a data availability problem, or some other kind of problem?  It certainly shouldn’t be a processing power problem anymore.”

[Surely FTA has heard of person-weighted averages. I am not sure why this should be a problem.]