Like Y2K and the Mayan prophecies concerning December 21, 2012, the apocalypse heading for New York City comes with that “mark it on your calendar” feature you just don’t get from surprise nuclear attack. Here, the end-of-the-world date in question is April 2019, when one of the key linkages between Manhattan and Brooklyn will shut down.

In 2012, Superstorm Sandy flooded the 92-year-old Canarsie tunnel, which takes straphangers under the East River, with 7 million gallons of seawater. So, in just over a year, the stretch of the L subway train that runs from the west side of Manhattan, along 14th St, and through the tunnel into Brooklyn will go on a 15-month hiatus. A full shutdown, the Metropolitan Transportation Authority says, is the best way to make much-needed repairs.

This presents a problem. Some 225,000 New Yorkers ride the L train through that tunnel every day—more than the population of Birmingham, Alabama. The subway line is the key connection between neighborhoods that have boomed in recent years—Williamsburg, Bushwick, Bedford-Stuyvesant—and Manhattan, where most of their residents work.

Since announcing its intention to make all those people find a new commute route in 2016, transportation officials have been working to manage the situation, and most of all, find ways to keep erstwhile subway riders from climbing into cars, in a city that already has some of the world’s worst traffic. This week, the city’s Department of Transportation unveiled new details for its plan.

And here’s the funny thing about this particular apocalypse: It just might save New York. The proposed plan reads like a urbanist’s Christmas list. It includes increased service on the lines to which most L riders are likely to convert (the JMZ, which runs over the Williamsburg Bridge, and the G, which connects to lines that run into lower and midtown Manhattan).

During certain hours, one lane of the Williamsburg Bridge would be reserved for buses, the rest for vehicles with three or more occupants. Much of 14th Street, a major crosstown corridor, would be closed to private cars, including taxis and ride-hailing services like Uber, Lyft, and Via. (With exemptions for trucks making deliveries, cars going to garages, and emergency and paratransit vehicles.) Buses would rule in their place, including a new bus rapid transit line, the eastern terminus for which will be the temporary dock serving a new ferry route. All told, the DOT aims to run buses every one to two minutes in each direction, each crossing the island in just 17 minutes—a 37 percent improvement of today’s average. The plan calls for increased bike-share service, expanded sidewalks on 14th Street, and better pedestrian access around Union Square.

It's an opportunity to show what the streets are capable of.

One block south, the DOT wants to sacrifice one lane of parking on 13th Street (that’s 236 spots) to make room for a two-way, protected bike lane. Delancey Street, the crosstown corridor to which the Williamsburg Bridge connects, would get better cycling infrastructure and more bus service, as well.

New York has faced similar crises: the aftermath of the September 11 terrorist attacks, a 2005 transit worker strike, Superstorm Sandy. After each, restricted transit service and private car use triggered spikes in cycling and walking—temporary spikes. But, given that this disruption is going to last for more than a year, New Yorkers might well adjust to the changes, to the point where these L train supplements feel like just one more part of the city’s transportation network—which means the city might want to keep them in place.

The bike lanes, for their part, fit into pre-existing plans to make cycling more popular and safer throughout the city and the DOT intends those to be permanent. You might not keep private cars off 14th Street forever, says Jon Orcutt, the former head of policy at the city’s DOT and now communications lead at the research organization TransitCenter. But maybe the grumblers will forget that the river crossings didn't always have carpool lanes, and increased pedestrian space is likely to be popular. For example, the shuttering of much of Times Square to vehicular traffic caused mild hysteria when it was implemented in 2009—but the resulting pedestrian plaza now feels integral to the area.

“We certainly hope that much of what works around the shutdown will be permanent,” says Paul Steely-White, executive director of the advocacy group Transportation Alternatives. New York is growing, and even once the L train roars back into full service, people will need more and better ways to get around. These tools may be born as substitutes, but they could live on as regular ol’ options.

“It’s a classic crisis opportunity,” says Steely-White. “An opportunity to show what the streets are capable of.” Not such a bad outcome for an apocalypse.

Life in the Jungle