In Washington, not all commuting distances are created equal

Generally speaking, our region's wealthier neighborhoods afford their residents more, faster options for traveling around the region than poorer ones, even if the wealthier ones are farther away from the core. The Washington Post recently ran two articles on this phenomenon that got a lot of attention, and I want to highlight and comment on some of their most important points.

The Post's first article, published April 15, is about inequalities in public transportation in the DC area and how they may be exacerbated by the coming Metrorail service reductions. Two days later came a pair of graphics that show the distances one can commute on transit at rush hour and in the evening, and the distribution of low-income households and transit riders in the region.

Wealthier neighborhoods to the north and west have better access to transit

Reporters Faiz Siddique, Armand Emamdjomeh, and John Muyskens start their article with this:

If you work in downtown Washington, don’t have a car and want to keep your commute to under an hour, you could live in Gaithersburg, Md., or Reston, Va., both about 20 miles away.

But you’d have trouble doing the same from just across the Anacostia River in neighborhoods such as Bellevue, only seven miles away, or close-in areas of Prince George’s County, Md.

The time it takes to commute the same distance by transit can vary greatly, depending on such things as how close one lives and works to a Metro station. However, the reporters found a much more systematic pattern in transit commute times. They compared travel times from downtown, both during the evening rush hour and late at night, and found that locations east of the Anacostia River and in Prince George's County tend to have longer transit trips to downtown than other areas similar distances away.

This is a particular problem given that a large fraction of the region's late-night workers live in these areas: the article notes that the Anacostia and Southern Avenue Metro stations have some of the highest numbers of late-night exits in the Metrorail system. Since late-night workers tend to be in fairly low-paid service-sector jobs, it is unsurprising that these areas of the region also have large concentrations of low-income households that are more transit-reliant.

As one of the graphics showed, the eastern side of the region is home to a disproportionate share of low-income households. A number of Census tracts in DC's northeast and southeast quadrants have more than 40% of their population transit-dependent and low-income. At the same time, job growth is highest on the western side of the region, meaning that these workers have especially long commutes that are only getting worse.

Bus service within Prince George's County is more limited than elsewhere outside of the District

The Post graphic includes a map showing places you can get to by bus from the ends of each Metrorail line within an hour after 11:30 pm. It's notable that Metrorail termini in Montgomery County and in Virginia tend to have relatively large areas accessible by bus from them, but those in Prince George's County mostly do not. This is in part testament to the unusually limited bus service in Prince George's County, especially on weekends and evenings.

Unlike other bus networks in the area, Prince George's County's The Bus network does not run on weekends or after 7:30 pm. The Post's map of income and transit ridership shows that the county has a disproportionate share of the region's population of transit-dependent poor households who are more likely to need late-night transit to get home from work.

The Post's article stresses transit times to downtown, but also notes that some suburban locations have better transit options for commutes to locations other than downtown than others. It's important to consider transit options that take people places other than downtown DC.

Further contrasts are illustrated by King Street in Alexandria, Va., and Largo Town Center in Largo, Md., which are seven and 11 miles from the White House, respectively. Despite only a few miles’ difference between the locations, commuters from King Street have access to a wide swath of the region — including Arlington and Fairfax counties in Northern Virginia, the District, and Montgomery and Prince George’s counties in Maryland — within an hour by transit. Commuters in Largo can reach only the District and Prince George’s, with the exception of some isolated pockets elsewhere in the region.

Many jobs, especially retail and other low-end service sector jobs, are not concentrated into downtown. And since people change jobs more frequently than they once did, and often live in multiple-income households, the ability to commute to a variety of places is only more important.

Bus routes from downtown mostly stop at the District border

The reporters write:

After the expected end of the SafeTrack program in June, Metro plans to move closing times for weekday service up half an hour, to 11:30 p.m. This change will significantly impact late-night transit coverage and the average of 2,600 riders who ride Metrorail from 11:30 to midnight on the typical weeknight, according to Metro ridership data.

The reductions in Metrorail's hours of service that will go into effect on July 1st will mean even earlier weekday and Sunday closures for what is already the rapid transit system with the earliest closing times in the county. The system will close later on Fridays and Saturdays to benefit those who partake weekend nightlife. But late-night workers on other days will become even more dependent on bus routes to get home after work.

Metrorail's earlier closing—the last trains will end their runs at 11:30pm, meaning that some trips will become impossible as early as 10:50pm—will mean that more late-night riders will need to depend solely on buses to complete their trips home. In order to get an idea of what this would mean for late-night commutes, I made a map similar to the Post's showing commute times by bus from Farragut Square at 11:30pm.

The structure of the DC area's bus network, which is largely designed to provide feeder routes for Metro, will make this early closing particularly problematic. As can be seen from the Post's graphic, bus service from locations inside the District largely terminates at the District's boundaries, and bus service in the suburbs is much more limited in the evening. I believe that this network structure, combined with Metro's early closing, makes it important that “night owl” shuttles following the routes of Metro lines be added to Metro's late night bus service.

This problem is becoming increasingly important as the District's housing costs rise, more and more low-wage workers are being pushed into the suburbs. We as a region need to think more about how to ensure that good public transportation is still available in affordable neighborhoods.

Correlation between income and transit ridership is surprisingly low

Included with the Post's map of transit ridership and low-income households were graphs showing Census tracts plotted by median household income and percentage of transit riders. The Post's discussion of these plots was focused on the concentration of low-income, transit-dependent households in the District, but I noticed another interesting pattern in them.

Washington has a higher concentration of low-income, transit-reliant residents than nearby counties in Virginia and Maryland. Many of those Census tracts lie across the Anacostia River.

But I was surprised to note that transit ridership seemed only very weakly correlated with low-income households in the District, uncorrelated in Maryland, and actually anti-correlated in Virginia. (That is, transit ridership in Virginia tended to be higher in neighborhoods with lower numbers of low-income households.)

It would be interesting to look at how this correlation has changed with time, and if it looks different if you distinguish transit riders who walk to the bus or train from ones who drive to a park-and-ride or station. I'm curious whether this has changed significantly due to gentrification in recent years, and due to poorer residents being pushed out into the suburbs, where the infrastructure for transit commuting is worse.

Did you read the Post's article and look at the graphics? What else did you notice?