It’s the busway or the highway — and that’s the problem.

Mayor de Blasio must set aside 40 miles of “emergency” dedicated bus lanes this summer to ensure that long-suffering transit riders — many of them essential workers — do not become prisoners of gridlock as the coronavirus pandemic wanes and cars flood back onto streets, four borough presidents and four major transit advocacy groups said in separate, but similarly urgent, messages on Thursday.

“City Hall must get out in front of rising car congestion,” the heads of TransitCenter, Riders Alliance, Tri-State Transportation Campaign, NYPIRG Straphangers Coalition and the Northwest Bronx Community and Clergy Coalition wrote to Hizzoner on Thursday. “Using materials like cones, barrels, and signs to mark off street space for transit, your administration can quickly deliver the improvements NYC bus riders need: 20 miles of busways and bus lanes serving medical facilities and other essential destinations by the end of June, then 20 additional miles this summer, focusing on streets in the Bronx and Queens that have already been identified for bus priority projects by NYC DOT.”

The groups centered the issue as one of basic equity and fairness, not just of basic transportation, calling a network of lanes “an urgent matter of racial justice, public health, and economic necessity.”

“Nearly half of regular NYC bus commuters are classified as essential workers. The vast majority are black and brown New Yorkers,” the letter continued. “They are tending to the sick and vulnerable, ensuring the city doesn’t go hungry, and keeping the lights on.”

The groups’ letter followed, by mere hours, a similar demand from all of the city’s four elected borough presidents.

“Bus riders, perhaps more so than any other transit users, deserve priority now,” said the letter sent by Manhattan Borough President Gale Brewer, Brooklyn Borough President Eric Adams, Bronx Borough President Ruben Diaz Jr. and Staten Island’s Jimmy Oddo. (Queens has not had a borough president since Melinda Katz become district attorney.)

“They are statistically likely to be lower income and therefore less able to afford the costly transition to a personal vehicle or car service,” continued the letter, which was first revealed by the Daily News. “Shortening ride times for essential workers would help minimize their exposure to the virus and reduce the stress of long commutes.”

In a press conference on Thursday, the mayor did not allude specifically to the letters, but told reporters that he’s thinking about what to do, but hasn’t done anything yet.

“Some people are comfortable going back to mass transit and others are not and that’s fine, that’s normal,” he said. “And we’ve heard from the essential workers even before this that they wanted to see improvements in mass transit. They want to see it cleaner, they wanted to see a more social distancing. They had seen some instances of crowding. We’ve been working with the MTA on all of this.”

Left unsaid was the mayor’s decision earlier in the pandemic to slash nearly $8 million from his own Better Bus Initiative. Also unmentioned was the mayor’s apparently broken promise to create new versions of the car-free 14th Street busway, a successful pilot program that began last year.

Riders Alliance spokesman Danny Pearlstein said the mayor can’t just wait.

“If the mayor sticks to a laissez-faire approach to transportation, gridlock will engulf ambulances and buses and destroy air quality,” he said. “More than ever, Mayor de Blasio must act decisively for safe, fair, and efficient streets.”

City Hall and the DOT did not return an immediate request for comment. We will update this story if they do.