Maps have suddenly become the preferred method for presenting information, which is a good thing. But I see so many maps that don’t present what they are claiming to present, or supporting the story being told in the text. Ack! Since coronavirus maps are the rage, I’ve selected two to show. These are from the […]

SacRT routes & population density

Investigating the proposed SacRT service changes (cuts), I identified that routes serving low density areas are a problem. I developed the map below (pdf SacRT_pop-density) showing routes and population density, with low density areas shown in red. Two routes stand out as servicing primarily low density areas, which are unlikely to ever be productive in a ridership sense. In fact, one of the reasons SacRT struggles to provide efficient transit service is the low-density nature of the county. Though of course agricultural areas north and south of the urbanized area will be low density, there are also large areas of low-density suburb and exurb (sprawl) which will never be successful. Every greenfield development allowed by the county and cities just exacerbates this problem

The population data is from the American Community Survey (ACS) 2014 5-year estimate (S1903), selected by census tract and matched to census tract outlines provided by SACOG, showing residents per square mile. The routes are from the Google Transit Feed Specification (GTFS) provided by SacRT. All routes are shown, including commute hours, low frequency, moderate frequency, and high frequency routes, as well as routes operated by SacRT under contract with others. It would be more useful to identify and/or separate out different kinds of routes, but it takes a while to compile that data, and I’m not quite there yet.

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I ran across a neat website, Social Explorer, which presents census data over time. I made a quick gallery for census tract data from 1950 through 2010 for the Sacramento region, and it is below. Before 1950, data is available only by county, not by census tract. I’ll be exploring this tool more in the future.