By CBS3 Staff

TRENTON, N.J. (CBS) — To keep a spike in coronavirus cases from happening here, a new travel advisory was issued by governors in New Jersey, New York and Connecticut. It requires people arriving from states with high coronavirus rates to quarantine for 14 days. Pennsylvania is not part of the new effort.

Gov. Phil Murphy said there won’t be border checks in New Jersey. Instead, people are being asked to take personal responsibility when they arrive here from other states with high rates of COVID-19.

Travelers arriving at Philadelphia International Airport will face new travel restrictions if they’re going to New Jersey, New York, or Connecticut.

They’re supposed to quarantine for two weeks if they’ve come from states with new outbreaks of COVID-19.

“It’s a really smart, common-sense step, particularly as we have, the three states have really broken the back of this virus,” Murphy said.

Murphy joined the governors from New York and Connecticut in announcing the new advisory, which says people coming into the three states from places with high rates of COVID-19 should self-quarantine for 14 days.

“It’s only for the simple reason that we worked very hard to get the truck through viral transmission rate down. We don’t want to see it go up, because a lot of people come into this region and they could literally bring the infection with them. It wouldn’t be malicious or malevolent, but it would still be real,” New York Gov. Andrew Cuomo said.

The mandatory 14-day quarantine currently applies to people traveling from Alabama, Arkansas, Arizona, Florida, North Carolina, South Carolina, Utah and Texas — the states experiencing spikes of COVID-19.

“The states themselves can change as the infection rate changes and we will update daily what states are above that infection rate,” Cuomo said.

The quarantine is based on a formula. If 10% of a state’s population tests positive on a seven-day rolling average, there is more widespread coronavirus. Nine states currently meet that criteria.

Experts say the virus is spreading in states that had limited restrictions and lifted them early. The opposite has happened in much of the Northeast, where there’s been a steady decline.

The new quarantine aims to keep newly-infected travelers from spreading it here.

“We’re asking folks to take on a big amount of personal responsibility here, to do the right thing,” Murphy said.  “We welcome everyone to New Jersey, but we simply ask you to join us in our shared sacrifice to keep ourselves moving in the right direction.”

The travel advisory starts Thursday at midnight.

An aggressive PR campaign will be launched at airports and train stations to make sure travelers are aware of the advisory.

It’s not the bustling Philadelphia International Airport we’re used to seeing but residents are still traveling during the pandemic.

“I think that everyone should make wise decisions when they travel. That’s common sense. You have to look out for yourself as well as for the other person,” traveler Glenda Showers said.

Showers is visiting from Arizona, which is one of nine states on the travel advisory.

CBS3 also spotted some Pennsylvania residents returning from a California trip.

“I feel like if you’re very precautious, if you use a lot of caution when you’re out, then you shouldn’t be that worried. If you were out without a mask, I definitely think you should be self-quarantining,” Reading resident Ramia Robinson said.

Cuomo said people who violate the quarantine in New York could be fined. Murphy said the New Jersey Health Department would be in charge of enforcement.

CBS3 reached out to Gov. Tom Wolf’s office to see if Pennsylvania will join this advisory. We were told, “Pennsylvania is prepared to ask travelers from hot spots to quarantine if deemed necessary.”

CBS3’s Stephanie Stahl and Kimberly Davis contributed to this report.