Drivers in Napa, California, over the Fourth of July weekend came across a surprising traffic sign warning people of “Asian drivers.”

A motorist pulled over to film the illuminated sign, which read “caution asian drivers,” on Sunday night, according to CBS Sacramento.

The original sign displayed a detour alert for a local bridge replacement project, Vince Jacala, a spokesman for California’s Department of Transportation, also known as Caltrans, told HuffPost on Friday.

Caltrans officials were alerted of the hacked sign late Sunday evening after a driver reported it to the Napa Police Department. Jacala said Caltrans immediately removed the sign once notified.

“Caltrans policy is to always lock the sign control boards which also require a secret code to operate,” Jacala said. He warned that anyone who sees an altered highway sign should contact authorities immediately “as bogus information can be not only be a distraction but also create a safety hazard.”

The prank in Napa over the weekend referred to a popular racist myth: that all Asian people are bad drivers.

Though people have been peddling the stereotype for years ― the Urban Dictionary entry for “Asian driver” is filled with racist and offensive descriptions ― it has no scientific basis.

In fact, studies have proven the “bad Asian driver” myth wrong. One 2011 study from Canada published in the journal Accident Analysis and Prevention revealed quite the opposite, with results suggesting that recent immigrants from China and India are less likely to be involved in a car crash than long-term residents.

Data collected from the National Highway Traffic Safety Administration also revealed that Asians and Pacific Islanders had the lowest car accident fatality rates of all ethnicities in the U.S. between 1999 and 2004.

Will these studies stop people from believing the stereotype that all Asian people are bad drivers? Probably not. And we’re pretty sure that petty signs like this won’t help either.