Police officers from across New Jersey were in Atlantic City Tuesday for a conference about drugs, as legislation to legalize recreational marijuana advances in Trenton.

The conference, Law Enforcement Against Drugs (LEAD), held a cannabis summit for the officers Tuesday. LEAD as a group has admittedly not been in support of recreational legalization. Leaders say that they hope that the summit is a chance for the officers to gain some knowledge.

If the bill is passed, recreational marijuana for adult use could be allowed as early as 2020. Officers would need to learn new laws. Under the current bill, marijuana would not be allowed in public, nor would it be allowed in an open container. But police officers would still need consent to search.

Sayreville Police Chief John Zebrowski says that he is concerned traffic accidents could go up under so-called "drugged driving."

"Marijuana is not a benign drug. There are negative consequences and as a result of that our concerns are great. In particular, how it’s going to impact our neighborhoods,” Zebrowski says.

The chief says that what is difficult for police officers is that they will need to measure impairment and not possession during a traffic stop. There is currently no strong means of testing for marijuana impairment, like a Breathalyzer can test for alcohol.

But members of the New Jersey Cannabis Industry Association say that tests are in the works.

“Right now Kentucky and Nebraska are working on oral fluids testing, which seems to be very accurate and efficient,” says Dara Service.

The legalization bill also calls for the expungement of people with marijuana-related drug convictions.

The full state Senate and Assembly will need to vote on the bill before it heads to Gov. Phil Murphy’s desk. But lawmakers in Trenton have not guaranteed a floor vote in favor of legalization.

The vote could happen by March 25.