Federal Transit Administration (FTA) forecasting workshops

Many years ago, I found an excellent resource for transit modelling: slides from a series of 2006-2009 workshops held by the US Federal Transit Administration (FTA) advising agencies applying for federal funding for rapid transit construction under the “New Starts” funding program. It’s very deeply buried on their website, and since then I’ve seen very few people reference this material, nor have I seen it assembled into a formal report.

So, for those interested – I’ve pulled together an easier-to-use table of contents to the three separate workshops, and tried to “deep link” into them to make it easier to browse and find the material. Enjoy!

UPDATE April 2016 – FTA has reorganized their website and the reports are no longer available there. I’ve mirrored everything here on my website.
Continue reading Federal Transit Administration (FTA) forecasting workshops

Consistency in Time Weights

Modellers all learn about the different components of transit trip travel time, and the “perceived” weights that people put on them. It’s a useful insight into how transit works, and I find it’s a great exercise for testing how “useful” a new transit service is. The trouble is, after learning about weights, everyone wants to customize them – for their economic analysis, for one component of their model, etc.  And analysis quickly gets inconsistent. Here’s why I think that’s often a bad idea – and why I think the weights used in transit assignment should be applied, unchanged, for all other parts of analysis.  (And it’s not just me – the US Federal Transit Administration made this exact point in a 2006 discussion.)

The scenario

Suppose that we have a four-stage model with different transit time weights: Continue reading Consistency in Time Weights

Jarrett Walker’s “Transit Network Design” course

walkerMy employer recently hired Jarrett Walker to run his Transit Network Design course. I’m a long-standing fan of Jarrett’s work and regularly recommend his Human Transit book to colleagues.

I quite enjoyed the course, and it triggered thinking in three main areas for me:

  • Pulses / Timed Transfer Hubs for low-density areas
  • Completing the Grid using capital investment
  • Designing for Coverage vs. Ridership on a single corridor: local-vs-rapid stop pattern

The course revolves around group “build a network” games, and those games will clearly play out differently depending on the attendance.  Our course included several staff who work on bus scheduling, several who work on rapid transit planning, and many in areas further afield.  That meant that each group had several experienced and numerically savvy staff, who could quickly get up and running with headways, frequencies and cost unit rates, without any tutorial. Continue reading Jarrett Walker’s “Transit Network Design” course

Organizational Patterns

coverWhat makes a big organization work well?

Prior to my current job, my full-time working life was mostly in smaller companies. But working in a big company is a very different beast – making many teams and divisions move together is quite a task.

Some time ago, a friend pointed me to an interesting Wiki discussion on project management ideas. I followed a few threads there and stumbled on a fascinating book: Organizational Patterns of Agile Software Development by Coplien & Harrison.

It’s essentially a collection of ideas for improving organizations: building, healing, repair and growth. It’s written in a straightforward, browseable format: “if you have this problem, try this idea to fix it.” The book’s written for the software industry, but I feel most of the ideas are applicable in a wide range of fields.

Reading the book, what did I take away? Continue reading Organizational Patterns

Transit Map Mashup (Tech Talk)

GTHA Transit MapA few years ago, I built a Google Maps app that combined the maps from several Toronto transit agencies all in one mashup map. I never got around to discussing the technical issues associated with that effort, and thought it might be worth writing up. This is an extra-technical post, covering the GIS / raster graphics / GDAL programming techniques I used to make the mashup work, for anyone else interested in trying a similar exercise. Continue reading Transit Map Mashup (Tech Talk)

Represent Data

I recently received an NGO request for the House of Commons members’ contact information in Comma Separated Value (CSV) format. I quickly found the helpful Represent website by Open North. This small group who has scraped government websites and created machine-readable versions of MP contact information, plus a minimal maps interface layered on top.

However, the Represent effort leans a little too “techno-elite.” The results are provided in the JSON format, a hyper-current, versatile and Web-buzzword-compliant format. But most NGOs I know are still struggling to figure out Excel, never mind anything more recent; and Excel can’t handle much more than CSV files (if even that – modern web-friendly text encodings like UTF8 don’t even work properly).

So, I put together a quick bit of Javascript to convert the Represent JSON format to CSV format, ready for Excel to use. This should be “live” – pulling the latest version from Represent each time. Here are links to a few of the Represent datasets:

Federal

Provincial

Moving Cooler, part 2


Six weeks ago, I wrote a first piece on the Moving Cooler report. In that post, I walked through some of the report findings:

  1. Scope and approach
  2. What would happen if we deployed a sensible “bundle” of policies all at once?
  3. How do individual policies compare, within that bundle?

In this post, I’ll continue by looking at:

  1. What about at a “maximum” level?
  2. Conclusions

What does maximum deployment look like?

In the previous post, I looked at a few of the “big impact” policies. At the time, I focused on the “aggressive” deployment level. In this section, I want to switch gears to the “maximum” deployment level and dive a little deeper. Continue reading Moving Cooler, part 2

Moving Cooler, part 1

Three years ago, an excellent report advanced my understanding of which transportation/land use policies can really help to tackle climate change. From all appearances, that report has disappeared beneath the waves without a trace; I’ve met few policy advisors who have read it.

The report is Moving Cooler, written by consultants at Cambridge Systematics in 2009. It’s a non-academic technical piece with good math but poor messaging and graphics, and while there was some promotion during the study process, I’ve seen no follow-through. Together, this probably explains why it went unnoticed.

I’ll walk through the report findings in four stages:

  1. Scope and approach
  2. What would happen if we deployed a sensible “bundle” of policies all at once?
  3. How do individual policies compare, within that bundle?
  4. What about at a “maximum” level? (Discussed in part two.)

My own perspective in this post will be to understand two questions:

  • How quickly can we realistically hope to reduce emissions within the transportation sector?
  • Which policies offer the greatest potential at a reasonable cost? (This will necessarily ignore other considerations, such as equity or acceptability. To me, the first question is “does it work?” and only then is it worth asking “is it fair?” and “is it politically realistic?”

The report itself was never freely available, but executive summary material and appendices were online until quite recently. As the report website has recently disappeared, I’ve reposted a few of the freely available items for reference:

Scope and Approach

There are three key items to be aware of when interpreting the study:

  1. The study scope focuses only on policies in two of four areas:
    • included: travel activity changes by reducing the distance travelled or shifting to more carbon-efficient modes of travel.
    • included: vehicle and system operations by improving traffic flow.
    • not included: vehicle technology, such as electric vehicles
    • not included: fuel technology, such as cellulosic ethanol Continue reading Moving Cooler, part 1

Climate Change & Online Discussion

In the web world, the public conversation about climate change on mainstream discussion and media websites is quite distorted. The comments sections are filled with poorly informed opinions (on all sides of the debate), personal attacks and disinformation.  (It’s widely documented that the fossil fuel industries and other motivated groups are pouring significant amounts of money into propagating disinformation.)  There’s really no meaningful “conversation” happening on most sites, the comments usually shed little real light on the subject at hand, and I don’t think anyone changes their mind by reading the comments. See some examples here

I find it fascinating how real conversations are underway in some places on the web, though. Slashdot is a computer-science-geeks site I’ve been reading for 10+ years, with a very politically diverse spectrum of people on it. If you looked at most political articles there, the discussion is all over the place — left wing vs. right wing vs. libertarians vs. communists vs. anarchists vs. more libertarians.

But the forum is moderated, and well-moderated. And when it comes to climate change articles, the audience is technical, science-reading, and smart. Of the thousands of comments posted on each article, the readers vote the “best” ones up in a fairly effective manner using volunteer moderators and meta-moderators. Most heavily-debunked “denier” talking points are thoroughly rebutted and often voted right out of view. See for example

My recollection from reading Slashdot 5-6 years ago was the opposite — that the debate was much more vigorous, with denier talking points being moderated up equally with climate science talking points. But after scanning several 2004-07 posts, I don’t actually see that — Slashdot’s community and moderation system seems to have effectively rebutted the denier talking points for quite a while. See for example

It speaks to me about the value of websites with a real defined “community” and good moderation systems. It’s possible to learn a lot about the subject by reading Slashdot’s comment sections today, even though the site’s articles alone are minimal or poor. It’s also possible to take an interest in the subject without being repulsed by the constant name-calling, YELLING and bad writing in most newspapers’ comment sections…

This also makes me wonder if our political system can gauge the public opinion effectively. Is the “public’s opinion” the raw, unmoderated comments of a newspaper — or is it what would emerge if online newspapers with a fairly democratic / meritocratic moderation system like Slashdot’s?  (Sure, political offices rely primarily on polling; but they still learn the nuances of public opinion from letters to the editor and other such sources.)

Food for thought.

Advances in Population Synthesis, the journal article

I’ve finally published my M.A.Sc. thesis as a journal article, under the title Advances in Population Synthesis: fitting many attributes per agent and fitting to household and person margins simultaneously.

This article is the preferred citation going forward; I think it tells the story best:

  • A brief summary of the key contributions described in detail in my thesis
  • A better explanation of the U.S. context and the applicability of this work outside Canada. Statistics Canada goes to great lengths to protect Canadian privacy, and some of my work was motivated by the particular difficulties associated with Canadian census data.

My thesis is still a good source for anyone wanting greater detail, or anyone interested in a clear explanation of some of the Canadian data sources I used.

Continue reading Advances in Population Synthesis, the journal article