Sunday, January 20, 2019

The breakdown of the numbers demystifies the tradeoffs being made in service networks

Very interesting. From What Cities Are Getting Wrong About Public Transportation by Andrew Small. Reports on the use of detailed micro-analytics to better frame and form urban transportation decision-making.

I live in an area where there are a lot of wealthy people eagerly lobbying for more money to be spent on public transportation that they won't use in order to free up the roads which they do. I always argue that you have to look at the whole picture of commute times and reliability and hours of operation etc. and when you look at the full range of demands, public transportation too often fails to meet the minimum levels of attributes being demanded.

From Small:
This can be exquisitely frustrating as cities task transportation leaders with tackling some of the country’s most daunting challenges, from reducing climate change to alleviating economic inequality. But a new report and interactive tool from the Institute for Transportation & Development Policy wants to make the leap to a low-car future feel less enervating by breaking the numbers into smaller chunks. They’ve developed a suite of “indicators for sustainable mobility,” aimed at helping cities measure their transit systems for better outcomes by taking a closer look at where and how they reach jobs and people.

To do that, the report digs deeper in the 2015 ACS data to get a more complete picture of how cities can improve their share of sustainable transport—that’s public transportation plus walking, biking, scootering, and any other means of moving around that doesn’t involve a car. No matter if this category makes up the majority of commuters, as it does in New York City (66 percent) or the extreme minority (Nashville, 4 percent), there’s more to say about how it reaches people, housing, and jobs in any given city. (For a wider comparison, the report also looks at mode share in four Canadian cities and transit access in four cities in Mexico)

[snip]

The result is a set of measures that can explain a lot more about what certain cities get right or wrong on transit, and what they can do to improve their lot. The key, the reports stresses, is getting a better balance between jobs, low-income households, and people in proximity to public transit.

In the chart above, you can see the power of density: Philadelphia and Boston benefit from compact city blocks, while Louisville and Charlotte suffer from sprawl. Transit networks in Denver and New Orleans reach plenty of jobs, but could improve by reaching more people; Memphis and Indianapolis, on the other hand, need more jobs located closer to frequent transit. (A spotlight report paired with the indicators gets further into the nitty-gritty for Dallas, Denver, and Nashville.)

Ultimately, the breakdown of the numbers demystifies the tradeoffs being made in service networks that say, a subway map or bus schedule cannot convey alone. It also underscores the importance of frequency, not just access. “If you’re doing well on accessibility indicators, but doing poorly on population near frequent transit, what that likely means is you have transit near people, but that transit must not be frequent,” says Chestnut. “If something leaves like once an hour, that’s not a great commuting option.”

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