A description of what the NY, NJ, and CT policies entail and don't entail is found in an excerpt from an ABC7NY report that can be read in full at the link. Anticipating that some may feel the approach will be ineffective, many discussions about pertinent legal and logistical issues can be found.
This example includes a legal scholar's opinion that "neither federal nor state governments have clear authority... to restrict travel between states, thus making it difficult to justify any sort of domestic travel restriction in court'.
How the New York, New Jersey and Connecticut COVID-19 quarantine will work
Gov Cuomo said the three states have determined, "a state can say, as a matter of public health, if you come into my state from another state, you must quarantine."
He said there will not be a roadblock checking license plates at borders.
"That is not a quarantine, that is a blockade," Cuomo said. "That's what the federal government threatened to do with us at one point."
Each state will do its own enforcement. "In New York, it's a travel advisory, you are informed you should quarantine for 14 days. If you go to a hotel, hotel clerk asks how come you are not in quarantine? You go to a business meeting, someone says, aren't you supposed to be in quarantine? You get stopped by a police officer who says, you are driving a car from Florida, weren't you supposed to be quarantine for 14 days," Cuomo explained. "Any of those mechanisms you can be detected as violating your quarantine. If you are violating your quarantine, you can be subject to a judicial order and mandatory quarantine. You could have to pay the costs of quarantine. There are also fines that go along with violating the quarantine. $2,000 for the first violation, $5,000 for the second, up to $10,000 if you cause harm."
Gov. Murphy said in New Jersey, constitutionally, they are not able to put up border checks around the state, so traveling from one state to another is allowed.
"I think what we are asking folks, this is an advisory, so it's more than a recommendation," Murphy said. "We are asking folks to take on a big amount of personal responsibility here and do the right thing for themselves, as well as their families, communities and the rest of us.
Cuomo said there will be no organized enforcement and no national guard checking people at airports, but he would prefer a person to get tested immediately upon landing, saying that it's "the best way to avoid infection."
"Some states brought in the national guard," he said. "I don't know that we will need that enforcement. You land, you are informed. We know you landed because the Port Authority has the flight manifests. We can follow up and check on you, or someone could file a complaint on you or you could be pulled over by police."
And if travelers don't quarantine and they get caught, Cuomo says there will then be a mandatory quarantine and fines on top of it.