Tennessee cities are working to implement a new law that allows handgun permit holders in the state to carry their firearms onto public transportation.

The Associated Press reported that Tennessee’s four major cities — Nashville, Knoxville, Chattanooga and Memphis — intend to comply with the law, which took effect July 1, but have so far posted vaguely worded rules that may leave riders confused as to what the policy actually is.

Transit authorities in Nashville, Knoxville, Chattanooga put the onus on riders to educate themselves on who’s allowed to carry guns, while Memphis authorities are still revising the wording of their policies but have begun allowing permit holders to carry firearms.

Nashville has changed its transit system’s code of conduct to only ban weapons that are “unauthorized,” but does not mention the new law.

Chattanooga’s revised transit policy mentions the law without explaining what it actually means in practice, while Knoxville signs were changed with similarly vague wording.

Lisa Maragnano, Chattanooga Area Regional Transportation Authority executive director, implied such wording was purposeful.

“We will comply with the law, we won’t encourage it,” she said in an email.

The new law, backed strongly by the National Rifle Association and signed by Gov. Bill Haslam in May, calls for cities and counties to either install metal detectors and post security guards at public facilities or allow lawful gun owners with handgun permits to carry their firearms.

The measure will also provide lawful gun owners with a private cause of action to challenge local firearms rules they feel are not being implemented properly.

While gun control advocates claim it could endanger the lives of commuters, gun rights advocates argue the law will have just the opposite effect by letting lawful gun owners carry their firearms as protection against those with criminal intentions.