Mayor de Blasio testily said on Monday that he would miss Gov. Cuomo’s deadline to devise a plan to ban cars from some streets so that residents could get outside without being crammed onto too-narrow sidewalks and dangerously crowded parks.

One day after the Big Dog told Hizzoner he had until Monday to present such a plan, de Blasio lashed out at Streetsblog — and, indirectly, advocacy groups and the Council Speaker — for asking whether a plan was coming together. The exchange is telling:

Streetsblog: So, you just went through a lot of very important information, which I know we all appreciate, but I did not hear anything about Gov. Cuomo’s demand that you come up with some sort of plan to ban cars on some streets to create more social distancing space. So is there a plan?

Mayor: I spoke to this yesterday in detail, Gersh, and nothing has changed between yesterday and today. I have talked about what I think makes sense to do as a first step. I’ve talked to the governor about it. Our teams are going back and forth on details. We’ll have a plan worked through in the course of the evening to get started with. But I’ve also said really clearly that how we start this week in this whole new reality is just the beginning and I’m reserving the right in the course of the week and the weeks ahead to say, hey, we might want to do more of something or less of something or something different. And that’ll be an ongoing conversation with the governor as well.

So, the first point, which I said I think real bluntly yesterday, is we need to determine how and where we can enforce this new reality effectively. And that begins with the places that people already do go to. And that any new places we create, even though it’s meritorious in many ways, if we create them, we then have to ensure there’s an enforcement mechanism to go with them. We already have that when it comes to parks, for example, we don’t have that when it comes to new streets being designated separately. So that’s going to be something we only consider one step at a time.

I understand [and] respect absolutely advocacy journalism [but] you’re looking at this from one prism, and it’s a good prism, but I’m looking at this through the prism of how do we enforce these challenging new rules and a whole new reality. That’s what I care about first here, it’s getting that part right.

The mayor’s comments came hours after Transportation Alternatives and Bike New York issued detailed guidelines for streets and strategies the mayor could immediately roll out. Council Speaker Corey Johnson supported some of the key recommendations — including creating “Summer Streets”-like car-free zones.

Thanks @GershKuntzman for your questions, shame @NYCMayor has decided to question you are a journalist each time he answers. Speeding and other aggressive driving is markedly worse. Cops are doing nothing about it, just like before virusworld.

— Steve Vaccaro Law (@BicyclesOnly) March 23, 2020

“Our first priority must be to create those alternative spaces in neighborhoods with the least open and green space so that density is reduced in the existing parks in those neighborhoods,” said Johnson, also calling on the city to allow block associations to close some streets, as the advocates did.

Johnson also differed with the mayor, who said for the second straight day that he would not close the city’s playgrounds, which cannot be properly sanitized, during the crisis. The mayor’s answer on Monday showed that he does care about open space, though he remains reluctant to take it away from car drivers for the good of the car-free majority of a city that is now the corona epicenter.

In a lot of neighborhoods in the city, the playground near your home may be one of the only open areas that you can go to, to run around and do anything. So, you take that out of circulation, certainly in a lot of our lower-income neighborhoods there’s just, unfortunately, nowhere near the amount of park space there should be. So, I’m very reticent to take away one of the few alternatives that a family may have for any exercise at all, during a time when everyone’s going to be limited in how much time that can be outdoors. But if we find it cannot be monitored properly, then we can do something very different.

It was exactly that logic that prompted the governor to demand that the mayor close some streets.

“You have much less traffic in New York City because non-essential workers aren’t going to work. Get creative,” the governor said on Sunday after visiting overcrowded city parks on Saturday. “Open streets to reduce the density. You want to go for a walk. God bless you. You want to go for a run. God bless you. But let’s open streets. Let’s open space. That’s where people should be — not in dense locations.”

Advocates said the mayor needs to act fast — and disputed his logic that car-free streets will need any special enforcement.

“If the city has enforcement resources for crowding in parks and playgrounds, it could use some of them to manage vehicle-free or vehicle-light streets,” said Jon Orcutt of Bike New York.

Transportation Alterternatives Executive Director Danny Harris said he is willing to be patient — but not too patient.

“Just because the city hasn’t hit the governor’s deadline doesn’t mean they should give up,” Harris said. “Essential workers like doctors and nurses need alternatives to subways and buses. People cooped up indoors need to get outside and move their bodies. More space on the streets allows these things to happen while helping New Yorkers break the chain of transmission.”

The governor’s office did not return a request for comment.