Typically, electronic roadwork signs are meant to signal to drivers that there’s construction or a detour ahead. But one that was spotted by area residents in Bethesda had a profane message.

The sign was near Jones Bridge Road and Connecticut Avenue, according to neighbors who posted a photo of the vulgar sexual message on the community’s Facebook page.

(Because of the nature of the message, The Washington Post is not posting a photo of the sign.)

Charlie Gischlar, a spokesman for the Maryland State Highway Administration, said in an email Thursday that his agency “investigated it as soon as we were made aware of the language.”

Gischlar said someone erroneously “tweeted that it was ours.” He said crews arrived and found that the sign belonged to Montgomery County. Officials at the state agency said they then reached out to county authorities.

The sign belongs to the Montgomery County Department of Transportation. Esther Bowring, a county spokeswoman, said in an email that a side panel was broken into and that as soon as officials were “alerted to the problem,” they “took immediate steps to secure the sign, change the message and install additional locks.” The sign may have been tampered with twice over the last few days, county officials.

It was not immediately clear who broke into the sign or when, according to county officials.

Ilana Knab, who lives in Bethesda, said she saw the sign near Jones Bridge Road just before 7 p.m. Wednesday as she was driving her 16-year-old daughter, Cassidy, to a cello lesson. Her daughter snapped a picture of it as they were stopped at a red light.

Knab said the sign switched every few seconds from a warning of delays to the vulgar message.

Knab, a mother of four, said she laughed when she saw the sign. She later posted a photo of it on an online neighborhood page. Many area residents suggested that it could be a statement about the building of the controversial, $2 billion light-rail Purple Line.

Many residents oppose the 16-mile line that would run between downtown Bethesda and Silver Spring. Others were frustrated when part of a popular trail was closed for the line’s construction.

Crews work on the Georgetown branch of the Capital Crescent Trail in Bethesda as part of construction on the light-rail Purple Line. (Katherine Shaver/The Washington Post)

Some passersby said online that the altered traffic sign may have gone up Tuesday and was turned off and then back on.

Knab shared some of the comments from the Facebook page of the East Bethesda Citizens Association, where she posted the photo.

Bethesda area residents posted their reactions to a profane road construction sign near Jones Bridge Road and Connecticut Avenue. (Courtesy of Ilana Knab)

It isn’t the first time motorists have seen electronic roadwork signs that have been hacked.

Last month, a flashing message board along Beach Drive in the District had a profane message about President Trump and one that said “Kill Nazis.” And in November, someone tampered with a road construction sign at a busy Virginia commuter lot and wrote a message about Democratic presidential candidate Hillary Clinton.

Taran “Hutch” Hutchinson, a spokesman for the Metropolitan Area Transportation Operations Coordination, said these types of incidents where transportation message signs get hacked do happen “every so often, but they are not widespread.”

Often, he said, they happen simply because someone failed to secure access to the message system.

“These situations creep up sometimes when you have a contractor working for an agency and they’ve brought in their own equipment and not secured it,” he said. When this type of messaging equipment is bought, Hutchinson said, the buyer is supposed to change the default settings so it will be secured.

Gischlar said that while he did not know how the Bethesda sign was altered, transportation officials should be careful about who has access to such equipment.

“It’s like your home email passwords,” Gischlar said. “You should change them and then limit them to just a few people who can actually manipulate the controls.”

Katherine Shaver contributed to this report.