Key takeaways

  • Most YIMBYs know we can boost housing supply by building densely, fewer contemplate how to do so by growing the regional commuting zone.
  • Historically, many regions were well-connected by regional and commuter rail services that linked small towns to core city jobs and amenities.
  • Sustainably growing commutable land benefits can help meet housing demand without compromising fiscal or environmental concerns.

Building more infill housing (homes built within the existing developed area) must be a component of growing housing supply in any region. Building near existing jobs and infrastructure is inherently high value and low cost compared to alternative sites further from jobs and with all-new infrastructure. Outside these areas, housing advocates often dismiss new housing development as sprawl.

We often imagine sprawl as an unappealing and unsightly landscape. Anonymous strip malls, pothole-marred highways, and endless congestion. But not all sprawl is created equal and growing the supply of commutable land can be a reasonable strategy to grow a region’s housing supply.

While growing a region’s land supply often results in a classical sprawl dilemma, it doesn’t have to. Classical sprawl has recognized negative traits like crippling infrastructure costs and inescapable highway congestion. But we can still grow the regional commute zones of big cities without the pitfalls of classic sprawl development. 

There is a third way to add housing supply. One with the benefits of infill development while expanding the land supply for homebuilding all while maintaining fiscal and environmental discipline. To achieve this, we focus on reforming underutilized commuter rail lines into a regional rail operating model and encourage development along traditional land use patterns in existing towns and cities with stations on the route. 

Growing the commuter zone to grow housing supply

We can use the Washington, D.C. area as a case study for this issue. The region has expensive housing and a mix of transportation systems that connect three states (Maryland, Virginia, and West Virginia) and the District into a single commuting zone. Housing costs generally track jobs access, with the highest cost housing being generally closer to the middle of the region and closer to stations on the WMATA MetroRail network.

In this context, Washington, D.C. Mayor Muriel Bowser’s push to add 36,000 new homes in the District by 2025, and her more recent push to add 15,000 housing units to downtown DC doesn’t just help the District meet its own goals. It’s taking pressure off other jurisdictions to build housing in uneconomical or environmentally sensitive places. Similarly, nearby Arlington, Virginia’s, plans to boost the city’s supply of missing middle housing benefits the region by pulling more housing close to jobs and infrastructure. But there is a ceiling to how much housing can be added to these places. In D.C.’s case, there is a literal ceiling in the “Height Act,” a federal law from 1910 that limits building heights in the District.

Martinsburg, West Virginia, is 77 miles from Washington, D.C. At this distance, the city is not geographically close to D.C., and economically it more closely resembles some of the struggling regions the Niskanen Center previously studied than a typical D.C. suburb. The average Martinsburg home price in 2023 is $255,000, compared to $640,000 in D.C. Median household incomes of $45,901 and $69,021, respectively. 

Despite its distance from Washington, D.C., Martinsburg is marginally commutable to the region’s core. It is served by one Amtrak and three commuter train round trips per weekday on an existing rail line built in the late 1800s. The city is about two hours by car or train to D.C. during peak commute times. This is a relatively long trip for a daily commuter. However, in this era of increasing hybrid work, so-called “supercommutes” are more palatable for workers who aren’t required to make the trip every weekday.

Martinsburg is also a charming city with a walkable downtown. Coupled with its relative affordability, it has what urbanists would call “good bones”.

Increased regional rail service into Martinsburg would unlock more opportunities for existing and prospective city residents who want to take jobs in or near D.C. that pay higher wages than local jobs, while paying lower costs for housing and other essentials.

Martinsburg’s current rail service is helpful, but not frequent enough to sustain a strong connection to the D.C. labor market. The service pattern, following the traditional AM and PM peak directions only, is also poorly suited to anything but “9 to 5” suburb to downtown office commuting. 

As Matt Yglesias and others have shown, transit project costs in the U.S. are unacceptably high. These high costs, particularly for rail, reduce project competitiveness in cost-benefit scoring. Reforming existing commuter rail lines to behave more like regional rail operations can provide improved utility to riders, improve operational efficiency and asset utilization beyond what’s possible with traditional commuter rail, and better compete for discretionary capital grants. 

Getting there from here

Highways are the most common “solutions” to improving regional job access. They are also often American transportation projects’ worst offenders when it comes to cost-effectively boosting transportation access. Without tolling that responds to demand, a traditional highway widening would do little to improve jobs access in a place like Martinsburg relative to the marginal cost of added capacity. Additional highway capacity would impose environmental costs from earthmoving along the mountainous route to D.C. This route would also require more auto-centric development around Martinsburg, consuming valuable forest and farmland.

Buses running in dedicated lanes or with other speed-boosting infrastructure–sometimes called Bus Rapid Transit (BRT) often appear promising for applications like this. But decades of experience show what should be a cost-effective transit mode frequently falls short of its promise. What high-quality bus services save in financial capital; they often consume in political capital. 

Consider this scenario: to speed buses past regular traffic during the busiest parts of the day requires dedicated lanes. These lanes must be built (which runs into the same cost problem as highway expansions). Or it means lanes are taken from car and truck drivers. These drivers will be upset and leverage their numbers to exert political pressure on decision-makers. The decision-makers then have a choice: they can support the project to maximize bus efficiency or dilute it to mitigate motorists’ political pressure. Only a few U.S. cities have enough transit riders to outvote drivers at scale.

While some cities like Indianapolis have notched BRT victories, frequently the end result is a bus project that fails to live up to original service projections. This happens because decisionmakers withhold necessary infrastructure to avoid a potential motorist backlash.

So how can transportation and land use policy makers better integrate a place like Martinsburg into the prosperous D.C. labor market? Can they achieve better integration amid remote work commute patterns without falling into the high-cost, low-benefit traps that often plague American transportation projects? In the long run, American cities must find a way to make room on our streets for all types of space-efficient modes. But when there are options to expand transit without a long political fight, they should be taken seriously. Legacy rail lines aren’t perfect, but they have the virtue of already existing, without taking space from drivers.

Reforming the commuter rail line connecting Martinsburg to D.C. into a proper regional rail service would improve access using the existing corridor and maximize benefits at moderate costs compared to other alternatives like highway expansions or a ground-up rail connection in a dedicated right of way. Similar reforms on the Boston MBTA rail network in 2021 traded some peak time trips for increased midday service and is expected to improve railcar utilization by 18 percent while better serving riders throughout the day.

Map showing commuter and intercity rail stations serving Washington, DC (WAS). Martinsburg, WV (MRB) is in the upper left.
Source: https://www.openrailwaymap.org

Delivering regional rail reform on this corridor should be relatively inexpensive. The entire route is double-tracked, capable of running trains in either direction on each track and includes several crossovers (places where faster trains can pass slower ones). With this level of existing infrastructure, reorienting the service model should not require large capital expense. A railroad like this one should handle a mix of 64 passenger and freight trains per day, and currently sees around 40 per day, including 19 MARC trips and 2 Amtrak trains. 

Following the German maxim, “operations before electronics, before infrastructure, before concrete,” meaningful service improvements should be achievable without reaching the more expensive “concrete” phase of improvements.  

A regional rail operating model connects the core cities to outlying areas evenly throughout the day. This facilitates a greater variety of travel patterns, including reverse commutes and midday or evening trips. Philadelphia’s SEPTA system is perhaps the best example of this operating model in the U.S., with the added feature of run-thru service in the downtown that makes cross-region trips easier and makes coordinating with other transit modes more efficient. 

In addition to providing better service, an all-day regional rail operating model makes better use of capital assets than commuter rail. In the worst case, a commuter train runs into the city once in the morning and out once in the evening. Fixed infrastructure like tracks and stations sit idle during the day, and operating crews are either paid to do nothing or go unpaid during the day between runs. This is a wasteful use of capital and operating funds relative to the alternatives. 

By contrast, regional rail runs the same equipment constantly throughout the day, unlocking much better utilization of rolling stock, tracks, stations, and operating crews. Another benefit is that trains do not need to sit idle in the center city during the day, consuming valuable land in yards or sidings.

Beyond job access, a recent GAO report cited quality of life benefits from replacing long driving commutes with rail transport and that residents benefited from improved access to education and medical services in the core city. Transit generally also allows more productive use of travel time compared to driving.

The same GAO report cited capital and operating costs as barriers to improving traditional commuter rail service to places like Martinsburg. As shown above, more economic benefits and improved efficiency are attainable. This study from the Greater Washington Partnership also demonstrates how adopting a reformed regional rail service model can provide more and better service for a given amount of operating subsidy. 

The benefit of expanded regional rail service doesn’t exclusively apply to places like Martinsburg. Residents of core cities like D.C. and inner-ring suburbs like Arlington will face reduced competition for housing from workers who choose to live further away in towns with reliable rail access. Core city and inner-ring suburb residents also benefit from increased access to recreational and other activities from the added outbound trips.

The other side of the bargain

Even with international best practices operating models, the cities served along the route need to allow more infill housing growth in the walkable neighborhoods near stations to fill the trains to an acceptable load factor. This growth should be technically easy to accommodate since infrastructure and public services already exist (and may even be underutilized in some areas). This should be achievable as existing land uses near the station sites skew toward abundant parking instead of higher value uses like homes and shops.

Recognizing that transit infrastructure and operations cost money, and that money often comes from a broader area than just the places with stations along the line, part of the bargain needs to be that cities along the line allow housing growth so that the taxpayers funding the improvements are getting their money’s worth. Massachusetts provides a model for this. The MBTA zoning law requires communities served by the agency to allow at least one district with by-right multifamily housing near a commuter rail, rapid transit, ferry, or bus station. The law also withholds some funding sources from communities that do not comply with the law.

This philosophy is a component of our white paper, and is applicable in a scenario where the existing cities on the line are relatively small, and current residents would benefit significantly from improved regional rail service.

Conclusion

America’s superstar cities can boost housing supply by bringing more land into the regional commuting zone. Better regional rail access can achieve this while providing spinoff benefits to otherwise struggling regions and big city residents alike without many of the perils of classic auto-sprawl. We should undertake the proven operating reforms necessary to serve travelers and make the best use of public funds in this era when rigid 9-5 commuting is becoming a thing of the past.

Photo Credit: iStock