Access Maps

I was in San Francisco a few weeks ago and took a combination of trains, buses and cars to get around the city. One of the things I found when taking the BART, the subway that serves the Bay Area, was that it was often very hard for me to predict how long it would take me to get somewhere. Granted, I've only been in San Francisco twice, but going into the trip I thought I would have a better grasp of how much time I needed to get different places. Instead, I found myself underestimating how long it would take to walk to or from a station, or the time I would need to wait for the train.

What I really should have been using is an access map like the one created by Dan Howard and Chris Pangilinan. Their interacting map allows you to pick a particular point in San Francisco, and then see what parts of the city you can reach in 15 minutes, 30 minutes, 45 minutes, and so on using just walking and public transportation.

So, for example, when I click on Market St and Van Ness Ave, which is right on the BART line, I get a map that looks like this:

Using the legend in the upper left, you can see the parts of the city I can expect to reach in 15 minutes (the blue), in 30 minutes (the green), or 45 minutes (the yellow).

The intersection of Van Ness and Market is right on the BART, and so access to the rest of the city is pretty great. You can also try somewhere close by, but off the main train lines, like 20th and Mississippi to see the changes in access:

It's really interesting to see the bands of color that come out of this tool. On the map above, you can see that the yellow band (reachable in 45 minutes) hugs a couple major train lines and roadways, particularly in the south east. The two maps I did above are what you can expect on an "average day", based on data from 60,000 trips. There are also modes where you can see what's reachable on a bad day (bottom 15% of trips), and on a great day (top 15% of trips).

I first came across this project in an article from The Atlantic's City Lab. They have some great links to access maps that are in the works in other cities. For example, a Washington Post article shows a new New York access map done by the Regional Plan Association that puts a spin on a traditional time-access map by combining the time it takes to get places in New York City, with what kinds of jobs are available.

So, in the example the Post uses, if you live in a certain point in mid-town, and want to commute a maximum of half an hour a day using public transportation, here are the places with manufacturing jobs that you can reach:

If instead you decide you can put up with an hour commute, and you buy a car, their access map shows by how much your possibilities expand:

I would absolutely love to do an access map here in Amman. One of the things I hear a lot is how variable commute times are day-to-day, which is absolutely true. But using Howard and Pangilinan's method of separating access maps into an average day, a great day, and a bad day, one could still get a much better sense of how long a given commute might take.

Of course the real power is as a tool for planners. As Pangilinian notes in the City Lab article, by tracking how access changes over time, you can have a metric for evaluating public transportation improvement projects.

So what might we need to get this done here in Amman? The Post article breaks down what went into the Regional Plan Association's access maps:

These latest maps were built with Census data on job statistics by industry and location, local traffic modeling data, public transit feeds and open-source mapping information from OpenStreetMap that enables route planning by foot, by bike, by car or by transit. Add all of that together, and it's possible to pinpoint any spot in the city -- theoretically in any city with available data -- and measure its accessibility to jobs or good public schools or hospitals.

We're still far away from having that kind of data here in Amman---after all, we're still working on a basic transit map at the moment. But nonetheless, it's great to see what kinds of informational tools are underway in places where the city is better understood, and is another spur to getting some good data here in Jordan.