One strange fact of New York City that we — the royal we of this city — never contemplate involves the logistics of moving a few hundred thousand people every day in between the borough of Brooklyn on the Island of Long and the borough of Manhattan on the island of, well, Manhattan. It’s just a thing that happens every day, but beginning in April of 2019, just over 15 months from now, the 225,000 people that use the L train’s Canarsie Tubes are going to have to find another way to travel under the East River. The L train shutdown, in the aftermath of 2012’s Hurricane Sandy, is hardly a surprise, but the MTA and NYC DOT have been mum on mitigation plans. We heard about an initial proposal to implement HOV3 lanes on the Williamsburg Bridge in October, but Mayor Bill de Blasio did not want to release those in the lead-up to his reelection.

On Wednesday, after months of waiting and New Yorkers growing increasingly frustrated by the silence, DOT and the MTA finally unveiled their mitigation proposal. The plans involve that HOV3+ restriction on only the Williamsburg Bridge; new inter-borough bus routes between Brooklyn and Manhattan; a core busway for 14th St. in Manhattan with a two-way bike lane on 13th St.; and increased subway service on nearby and connecting lines. I have seen the public release DOT has put out regarding these plans and a presentation with more detail regarding the mitigation efforts. Today’s announcement “identified specific corridors and related transportation modes” targeted for mitigation, per the DOT release, and the agencies will next assess the “timing and scope” of various vehicular restrictions and transportation improvements. While these plans are not horrible, they’re also not great, and DOT seems to be afraid to tell single-occupancy car drivers that they’re banned from certain streets during the L train shutdown. Furthermore, that DOT and the MTA aren’t considering HOV3+ restrictions and a busway as 24/7 requirements off the bat is already concerning.

The images in this post are from the internal presentation. DOT’s release provides more context, and I’ll offer up some of that context as I discuss the images. Ultimately, this plan will be subject to public comment, and DOT and the MTA have vowed to revise it. It is also premised on the hope that at least 70 and perhaps as much as 80 percent of the L train riders will use alternative subway service to travel between Manhattan and Brooklyn. To that end, the two agencies believe that anywhere from 5-15 percent will utilize buses, and they are planning for 3800 bus riders per peak hour across the Williamsburg Bridge. Meanwhile, 3-5 percent are expected to use expanded East River ferries, but how the remaining 10-20 percent get around could be the difference between crushing congestion and a successful mitigation plan.

For better or worse, the underlying theory of mitigation divides the Canarsie Line into zones. Unavoidably, this division raises concerns about class and the socioeconomics of the L train that DOT and the MTA haven’t sufficiently addressed. Essentially, though, L train riders in zone 3 – and particularly those south of Broadway Junction who make up only 11% of Manhattan-bound riders — have numerous other subway options for access across the East River. Those in Zones 1 and 2 make up just shy of 50% of the L train’s Manhattan bound ridership during the A.M. peak hours, and they have worse access to Manhattan-bound alternatives. With 57 percent of the morning commute bound for north of 14th St., DOT and the MTA need to transport a lot of people across the East River in some way, shape or form that does not grind the city to a halt.

So what’s the plan for Zones 1 and 2? That HOV3+ lane on the Williamsburg Bridge and added bus shuttle routes. Take a look:

The bad news: As Polly Trottenberg stressed to reporters on Wednesday afternoon and as DOT’s document mentions, DOT is considered these lane restrictions “during rush hour at a minimum.” Based on L train ridership patterns and the impact of this shutdown, the HOV3+ lane should probably be a bus-only lane and should definitely be in place on a 24/7 basis for the duration of the shutdown. But here’s the story: The lanes will run from Grand St. in Brooklyn to Spring St. in Manhattan with bus service to the Essex/Delancey, Spring St. and Broadway/Lafayette-Bleecker St. subway stations. Additional bus priority lanes will be in place on both ends of the Williamsburg Bridge, and three new bus routes will provide inter-borough connections — including one that deliver riders to the 14th St. corridor. It’s not yet clear how HOV3+ enforcement will be implemented on the bridge, but enforcement will be key to ensuring buses can move freely. As to the other free East River crossings, DOT says they will “continue to analyze” how this plan will impact traffic on the other crossings.

But what happens when you get across the bridge? Right now, the focus is on the 14th Street corridor — a stretch of the L train that sees 50,000 passengers a day. That’s more than the busiest bus route and a ridership 66% higher than on the current M14 route. (Brooklyn-only travelers account for 125,000 trips per day on the L, and they’ll have service between Bedford Ave. and Canarsie at six-minute headways during the shutdown.)

The MTA and DOT did not embrace calls for a full Peopleway and have instead opted for what they are calling a “Core Busway” between 3rd Ave. and either 9th Ave. heading east or 8th Ave. heading west. Only buses and local deliveries will be permitted on those blocks with a major wrinkle — for now DOT says these restrictions will be “rush hour restrictions.” This is, in my view, a big mistake, and as I mentioned, any plan that isn’t 24/7 is doomed to lead to confusion and, worse, congestion. But again, this is a pattern of DOT shying away from inconveniencing drivers at the expense of pedestrians and transit riders.

Anyway, the agencies have adopted this “Core Busway” approach rather than a full busway because they feel it has less impact on bottlenecks, particularly near Alphabet City and a more distributed effect on traffic on nearby local streets. A block to the south, DOT plans to create a two-way protected bike lane down 13th Street, and Trottenberg did mention they hope to maintain these bike lanes after the shutdown. Again, enforcement on 14th St. remains an open question.

And what of the subway improvement plans? So glad you asked.

As the MTA and DOT anticipate that “alternative subway routes will carry the large majority of L riders,” the MTA plans to implement service increases throughout the subway system. I have been told that 480-foot G trains may run as frequently as every 4 minutes, and the MTA will implement MetroCard transfers between the L and 3 at Livonia/Junius, between the G at Broadway and J/M/Z at both Lorimer and Hewes Sts., and between the G at 21st St. and 7 at Hunters Point Ave. The M will run to 96th St. and 2nd Ave. during weekends and late nights.

The MTA also plans a series of passenger flow improvement efforts along the J/M/Z lines and at certain G train stations, and station entrances at three stops will be reopened. It’s not clear though how these subways lines will handle the increased capacity as it may be challenging to fit another 160,000 riders per day on trains that are very crowded as they cross the East River. This plan does not yet seem to add capacity to the A/C trains, the 3 train or, more importantly, the Queens trains, and riders of the 7 and E trains in particular are very concerned that the L train shutdown will completely overburden lines that simply cannot hold more passengers.

The shutdown, as I’ve discussed in the past, will include some system improvements to the L train stations, and I’ve heard rumors of a new escalator down to the L train platform from the mezzanine above the IRT at Union Square.

In addition to these specific improvements, DOT and the MTA are going to explore “major changes” to Grand Street in Brooklyn that could turn that road into a bus and bicycle corridor, and DOT is hoping to increase Citi Bike capacity throughout the impacted areas. So that’s the plan for now, and it’s going to evolve with more detail and more public input. But the lack of 24/7 commitment and, for example, the fact that DOT hasn’t acknowledged the impact for-hire vehicle services will have on surface congestion still make me worried that DOT in particular is underestimating the impact of the L train shutdown on the city at large. Those 225,000 rides per day aren’t just going to end up on an overburdened J train without significant work toward making rides tolerable.