State-level departments of transportation love putting funny or topical messages on digital traffic signs, but new rules at the federal level might bring the fun and games to an end.

To be clear, this isn’t about, but the when there isn’t anything timely to update drivers on—like road conditions or traffic issues. States find fun messages are more memorable than the everyday warnings about seatbelt wearing and speeding.

Even so, the Federal Highway Administration is currently looking to change its rules for traffic signs. The draft for an upcoming update to the FHWA’s hefty Manual on Uniform Traffic Control Devices reflects a 2021 ruling which found the signs were getting just a little too clever. From the :

The of the revised version includes guidance that comes down firmly against such messages.

“Messages with obscure or secondary meanings, such as those with popular culture references, unconventional sign legend syntax, or that are intended to be humorous, should not be used,” the draft says.

Some states and safety advocacy groups have pushed back, calling for that language to be struck from the manual. Martin said such a provision could leave federal highway officials in the position of judging just how funny is too funny.

“You start getting into having to make subjective value judgments about things,” he said.

The feds called out New Jersey in particular in recent years for its sassy traffic signs, even receiving a cease and desist letter from the federal agency’s New Jersey division.

The effectiveness of witty signs is up for debate. States love them, as it earns DOTs some fun publicity and even occasional notoriety on social media. Plus it seems like making a message witty, topical, or full of puns should be better at grabbing drivers’ attention. One study even shows that such messaging causes more activity in the reader’s brain than a simple message like Don’t Drink And Drive, the Post reports.

The National Academy of Sciences, however, measure the response of 120 people to look at a variety of road signs. The Academy concluded that straightforward road signs were the most effective. That’s important information, considering a nationwide spike in traffic deaths. Funny signs might make a boring chore like freeway driving more entertaining, but if it’s not making us more safe, then what’s the point?