New York City on Tuesday unveiled a public service campaign urging New Yorkers to stay home as much as possible during the upcoming holidays.

Health officials are bracing for a dangerous surge in coronavirus cases as families prepare to gather for Thanksgiving. For several weeks, testing sites across the city have witnessed long lines of people seeking tests, with many on line saying they wanted to get tested before traveling to visit relatives.

Despite strong recommendations from public health experts to avoid travel, there are clear signs that many Americans still intend to do so. This past weekend, more than 3 million travelers filed through U.S. airport checkpoints, the busiest weekend since the pandemic began in March. New York state currently requires a two week quarantine for anyone entering New York after spending over 24 hours in another noncontiguous state or country, though travelers who test negative for COVID-19 after arriving can end their quarantine early.

"It's not too late to cancel your travel plans," said Dr. Dave Chokshi, the city's health commissioner, during a morning press briefing with Mayor Bill de Blasio at City Hall.

On Tuesday, the mayor reported that the city had a seven-day test positivity of 3.17%. The total number of new daily virus cases continues to climb, with the seven-day average of new cases now above 1,400.

Chokshi said the new ads, which say "Stay Safe Stay Home," will be displayed on mass transit as well as throughout the city until January.

Similar to an effort before Labor Day weekend, Mayor de Blasio announced that the city would install vehicle checkpoints at major bridge and tunnel crossings as well as at bus stops. The roughly 150 members of the Department of Finance's Sheriff's office will be tasked with distributing information on the state's quarantine rules. Travelers who either fail to quarantine or get tested upon their return to New York face a mandatory quarantine order from health officials or a maximum fine of $2,000.

According to city health officials, at least 12% of cases over the last four weeks have been associated with travel.

Yet despite stern warnings from both the mayor and Governor Andrew Cuomo, there has been only one reported arrest: a Florida man who had checked into a Midtown hotel in September but was issued two summonses by city sheriff's deputies when he was found missing from his room.

Asked about enforcement, de Blasio noted that the sherif had succeeded in shutting down several large illegal gatherings. Over the weekend, the Sherriff's office shut down a Queens sex club where more than 80 people had gathered for a party.

"It’s a big city, over 8 million people, it’s a huge geography to cover," the mayor said. "Overwhelmingly, I give them a lot of credit."

During a press conference in Long Island, Cuomo also implored New Yorkers to refrain from large gatherings. Under a state rule, no more than 10 people are permitted for private indoor gatherings.

The governor said a 20% increase in cases from the holiday season, which is considered a relatively modest projection, would mean that the statewide positive test rate would reach 12% by January 2nd. The state's positivity is currently a little under 3%.

Cuomo himself came under scrutiny on Monday after he revealed he was planning to gather with mother and two of his daughters for Thanksgiving. “My mom is going to come up and two of my girls,” he said, during a radio interview with WAMC's Alan Chartock, although he conceded that his plans could change.

Following criticism from state Republican lawmakers, the governor reversed course and issued a statement saying that he planned to work through the holiday.

On Tuesday, Cuomo spoke of not wanting to disappoint his 89-year-old mother.

"It’s hard but sometimes hard is smart," he said.