How to Save Money and Time on Second Avenue Subway (Bonus: New Housing)
A team of urban planning scholars at New York University’s Marron Institute of Urban Management has released a proposal to expand subway service throughout New York City that could, if implemented, jumpstart the creation of 19,985 units of new housing (4,872 of them affordable homes) along just one line of the new route: the long-planned (and long-delayed) Second Avenue subway, as it is extended from the East 50s into Lower Manhattan. As a bonus, the plan would spend money already allocated and build the Second Avenue line for a fraction of its estimated cost.
Professor Eric Goldwyn, the Marron Institute’s program director for Transportation and Land Use, who led the team of seven researchers that produced “A Better Billion: Expanding Transit & Housing for a More Affordable New York,” explained, “our proposal doesn’t require any new zoning. It works entirely within the framework of incentives created by City of Yes/Housing Opportunity,” a rezoning initiative formulated by then-Mayor Eric Adams and enacted in December 2024.
Professor Goldwyn continued, “the surest way to achieve Mayor Mamdani’s goals related to affordability is to focus on the cost of housing. This gets easier when you create incentives to build more homes, like those contained in City of Yes. But building new infrastructure is another key way to achieve this. Developers have a powerful reason to invest in new homes when a subway line nearby increases the value of those properties. And City of Yes has built-in affordability requirements.”
The version of the Second Avenue subway extension conceptualized by the “Better Billion” report would dig a new north-south tunnel on the east side of Midtown (as currently planned), but this tube would extend only as far as Chatham Square, in Chinatown. From there, the Marron Institute team proposes to merge the Second Avenue line into the existing tunnel and tracks for the J and Z trains (along Nassau Street). The Second Avenue train would stop at the current J and Z stations at Fulton and Broad Streets, in the Financial District – both of which would need to have their platforms extended – before entering the existing Montague Street Tunnel, and continuing to Brooklyn. (This is another point of contrast with the “official” Second Avenue plan, which would have the line terminate at Hanover Square, potentially limiting its usefulness.) “The J and Z trains operate at well under the capacity for those tracks and tunnels,” Professor Goldwyn said. “We need only to improve the stations.”
The Marron Institute team estimates that their proposal would save several billion dollars, compared to the current Second Avenue plan, which entails digging a new tunnel all the way to Hanover Square and carving multiple new stations out of solid bedrock, rather than repurposing existing stops. “Lower Manhattan’s exceptionally high density of local subway stations makes it less necessary to build new stations slightly father to the east, as now planned,” explained Professor Goldwyn, “and this means the new tunnel to Hanover Square is completely unnecessary. The trade-off is to save billions of dollars and years of construction work.”
Digging new subway tunnels is staggeringly expensive. (The initial phase of the Second Avenue subway, which opened on the Upper East side in 2017, cost $2.5 billion per mile.) So how does the Marron Institute team hope to fund this plan? “Making bus service free, as Mayor Mamdani has proposed, would cost roughly $1 billion per year,” Professor Goldwyn observed. “Our entire plan – not just for the Second Avenue line, but for more than 40 miles of new subways – could be funded at $1 billion per year, over the next few decades.” Thus, the report’s title: “A Better Billion.” The Marron Institute team estimates that its concept for extending the Second Avenue from the east side of Midtown to Lower Manhattan could be built for $9.3 billion.
Professor Goldwyn added, “subways are a transformative investment that changes everything. They can bring so many people in and out of a location so quickly and cheaply that they create many other options and opportunities, not only in housing, but also job creation. All of which generates more tax revenue. So, this is an investment that pays dividends in other ways and other forms, for decades into the future.”
As the “Better Billion” report notes, “the subway has always been New York’s secret weapon. It allowed New Yorkers to escape overcrowding in Lower Manhattan and spread out across the five boroughs while maintaining intense residential- and job-density in Manhattan. New York’s density has served it well. It has enabled 8.5 million people and five million jobs to flourish.”
For the new housing development that would be catalyzed by this plan, “our team looked at all building lots within half a mile, or about a ten-minute walk to the new subway stations we propose,” Professor Goldwyn explained. “We then calculated how much more density each of those lots could legally be upgraded to, under City of Yes for Housing Opportunity, and estimated how many new housing units would result from the development catalyzed by the new subways.”
These tabulations found 257 parcels of land along the planned Second Avenue subway route, with 12.9 million square feet of unused development potential. This space would yield more than 19,000 new homes, with slightly fewer than 5,000 of them required to be affordable, under City of Yes zoning mandates.
For the City as a whole, the corresponding metrics are 30,700 building lots within half a mile of the 64 new subways stations that the Marron Institute team proposes to build along 41 miles of new tracks. On these parcels, the “Better Billion” report estimates there is legal development capacity for more than 167,000 new residential units, more than 38,000 of which would be subject to City of Yes affordability requirements.