A prototype drone test sprays paint to cover up graffiti in Tacoma earlier this spring. (Courtesy of the Washington State Department of Transportation)
Using aerial drones to spray paint over graffiti along state highways is “very effective,” according to a new report from Washington’s Department of Transportation.
Over the last six months, the agency has tested graffiti removal methods through a pilot program set up by the Legislature last year. Lawmakers set aside $1 million for the department to focus on new ways to erase spray paint from road signs, walls and bridges.
The agency spends thousands of hours and hundreds of thousands of dollars each year on graffiti removal.
While the drones are useful to reach spray paint in places that are dangerous or difficult to access, the agency said in its report that other maintenance needs may be higher priorities for funding.
“Graffiti removal is and will remain a challenge,” according to the report.
The amount the state spends on graffiti cleanup every year has been on the rise.
In 2023, the department’s crews spent more than $815,000 on graffiti removal statewide, the agency wrote in a blog post. The department estimates that’s nearly 10,300 hours of labor and 700,000 square feet of graffiti. Removal costs about $3,000 per tag.
At the time the pilot program passed the Legislature, sponsor Rep. Andrew Barkis, R-Olympia, said graffiti along Washington’s roads was “getting out of control.”
The program helped the agency train two drone operators and remove graffiti in the Tacoma area along Interstate 5. It also paid for equipment and supplies.
To date, the department has spent $22,000 to clean graffiti using drones and has plans to spend up to $60,000 on these efforts through June 2025.
The drone that the department is using was purchased before the Legislature allocated money toward this effort. It’s an $86,000 aircraft powered by batteries and tethered to pump paint from the ground. The department is in talks with a supplier to create a self-contained unit that holds one to two gallons of paint without a tether, which operators say can get caught on trees or billboards.
Along with using drone technology, the Legislature encouraged the department to look for ways it can use cameras to catch illegal graffiti activity, focusing mostly on the I-5 corridor between Tacoma and Seattle and the North Spokane Corridor.
Over the last six months, the agency tested four different graffiti detection devices set up in two locations in Tacoma and Spokane. The devices, which include cameras or radar, use artificial intelligence or machine learning components to recognize a graffiti tagger.
When a vandal is spotted, the devices send a notification to a traffic management center operated by the Department of Transportation.
Each device was only active for a few weeks in October due to time constraints related to when the department must spend the money provided for this work. That short period limited the opportunities for the devices to catch taggers, according to the report.
But one device in Tacoma, which was active from Oct. 9 to Nov. 5 resulted in three notifications on graffiti activity and one arrest.
“Although the number of opportunities to detect taggers in this pilot was low due to the quick turnaround, the proviso provided evidence that the technology exists to detect graffiti taggers in real time,” the report reads.
Still, funding limitations and Washington State Patrol staff shortages are constraints, the department says. And, at this point, the agency has no proposal to fund graffiti detection past next June.