Checkpoints will be set up at New York City's tunnels and bridges to trace travelers from 35 COVID hotspot states and enforce 14-day quarantine - and anyone who flouts it risks a $10,000 fine

New York City Mayor Bill de Blasio said on Wednesday he was introducing checkpoints at tunnels and bridges to trace travelers coming in from COVID-19 hotspot states and force them to quarantine, but failed to explain how he would enforce it. 

At a press conference on Wednesday morning, de Blasio sternly warned travelers that the law was 'serious' and that they could face a $10,000 fine if they do not self-isolate for 14 days once they arrive in the city. 

The checkpoints will go up on Thursday but it remains unclear exactly where. 

They are to identify people traveling into the city from one of the 35 states on Gov. Andrew Cuomo's mandatory quarantine list; Alaska, Alabama, Arkansas, Arizona, California, Florida, Georgia, Iowa, Idaho, Illinois, Indiana, Kansas, Kentucky, Louisiana, Maryland, Minnesota, Missouri, Mississippi, Montana, North Carolina, North Dakota, Nebraska, New Mexico, Nevada, Ohio, Oklahoma, Puerto Rico, Rhode Island, South Carolina, Tennessee, Texas, Utah, Virginia, Washington, Wisconsin.