For their piece on food deserts this week, National Geographic led off with this map of Houston. It shows where large numbers of people who lack cars are located more than 1/2 mile from a grocery store.
"Public transportation may not fill the gap," the article says, but sometimes it can. The article doesn't mention it, but Houston METRO's proposed System Reimagining will actually liberate many people, but not all, from the "food desert" problem.
One thing is for sure: When we're talking about errand trips like groceries, most customers don't have a lot of time. If there's a line to check out of the grocery store, and you miss an hourly bus, you'd better not have bought anything that needs refrigeration, and certainly nothing frozen. So as always, frequency is freedom.
So if you need frequency, Houston's transit system today is basically willing to take you downtown, which is not likely to be the path to your nearest grocery story. Here's the frequent network today.
It's radial, good for going downtown but not for many other purposes. If you're lucky it will take you to a grocery store, but more likely it misses the ones nearest you. And of course you may not be on this network at all.
Here's the reimagined frequent network:
Compare this to the food desert map (to see the detailed Reimagined network maps, see here) Many of the areas of concern, especially those in the southeast and southwest, get a much richer network in a grid pattern. The grid pattern means ready access to many commercial centers in your part of town, not just to the major destinations of the region. And of course, a much larger share of the "food desert" areas are on this network, so that they can make shopping trips that take an hour instead of all afternoon.
Another crucial thing about the grid is that by running in all directions, it cuts across socioeconomic divides. Low-income people can get out of their enclaves to reach both jobs and commercial services in more prosperous areas nearby. (This frightens some people on the upper side of these divides, but it's one of the basic ways that good transit that's broadly useful creates paths out of poverty.)
(Remember: Most low-income people are busy! They have to be frugal with time as well as money!)
Not all the "food deserts" can be healed with transit. Some of the highlighted areas on the food desert map are in the northwest and northeast, outside of loop 610. Low-income housing in this area takes many forms, but a lot of it is semi-rural, and the built environment is often very hostile to both pedestrians and efficient transit routing. Some of these areas also have declining population. Our plan does try to offer some options in these areas, but transit is not the primary solution to the food desert problem there.
But over a very diverse range of Houston, the way to get low-income people to decent healthy food is the way you achieve so many other benefits: environmental, economic, and social: an abundant frequent transit system, in a grid pattern, that reaches across all the parts of the city that are dense enough to support it.