Graffiti drone pilot program takes flight

By April Leigh & Tina Werner

Graffiti-battling drones. It almost sounds like something you'd see in a sci-fi movie. They could be coming soon to a bridge or overpass near you.

Our Tacoma area maintenance crew, led by Mike Gauger, is testing drone technology that can remove graffiti from hard-to-reach places. The team is learning how these drones operate, how they apply paint and if they can cover graffiti.

The drone, built from an Aquiline Endure model, uses a spray nozzle and is linked to a paint supply on the ground.

A prototype drone test sprays paint to cover up graffiti in Tacoma earlier this spring

An operator on the ground can position the drone anywhere the tethered hose can reach. This could - make quick work of painting over graffiti on tall retaining walls, bridges and overpasses.

The problem

Graffiti damages state property. It also is a challenge for our maintenance crews to address. More importantly, it puts the people who participate in the activity and our own crews at risk. Under Washington state law, graffiti is illegal.

Tall bridges and overpasses are targets for graffiti and difficult for crews to clean up

Graffiti removal is part of our maintenance program. The same program patches potholes, repairs guardrail and culverts, and handles snow and ice response. In 2023, our maintenance crews spent over $815,000 on graffiti removal statewide (including staff time and equipment). That's nearly 10,300 hours of labor spent covering 700,000 square feet of graffiti along our highways. But that's still not enough to remove all the graffiti that appears along our highways.

Our crews report seeing new graffiti appear sometimes days or even hours after an area is cleaned.

An inventive idea

Mike remembers the exact day two years ago he got the idea for a graffiti-fighting drone.

For the second time in one week, Mike had to send a maintenance team to paint over graffiti on the Capital Boulevard Bridge in Olympia. Our crews prioritize the removal of graffiti that contains offensive or obscene images or profanity because it is distracting to drivers.

Mike knew the graffiti had to be removed, but it was frustrating to pull a bridge maintenance crew from another task. Plus, there's an equipment challenge. Specialized trucks, called UBITs, are needed for hard-to-reach graffiti. These trucks are in high demand, and we have six of them to cover the state. They are usually reserved for higher-priority bridge maintenance and inspection work.

After scheduling the work, he thought to himself, there must be a better way to get paint up there.

Crews at the State Route 16 Tacoma Narrows Bridge using drones equipped with high resolution cameras to complete inspections last fall

Then, he had a lightbulb moment. He was working with the Tacoma Narrows Bridge team using drones for bridge inspections. The drones, equipped with high resolution cameras, were decreasing the number of times crews had to physically inspect underneath the girders. That meant improved employee safety, less time on the inspection and overall cost savings.

If drones could be used for inspections, why couldn't they be used to spray paint?

Bringing it to life

Mike brought the idea to our maintenance director, who suggested a grant for a pilot program to research the idea.

Mike researched the use of drones with several manufacturers who produced similar products, and learned that there were no drones being designed to do things like this. He reached out to some drone manufacturers and found one that was willing to collaborate on the design of a prototype system.

Mike flying a test drone during research and design last fall

The team worked together on the design for months. Their first attempt malfunctioned in early testing, which gave them the information they needed to make adjustments. A final working prototype was delivered in spring of 2024.

We are the first transportation agency to pilot the use of drones to combat graffiti.

House Bill 1989

In 2024, the Washinton legislature passed House Bill 1989. The bill provides us $1 million to research traffic camera technology for monitoring graffiti removal. A small portion of the funding will cover crew labor and paint for prototype drone testing for the rest of the year.

We are in the preliminary phase of identifying and researching implementation of the bill.

In December 2024, we will submit a report to the Legislature about the facts and findings of the pilot program for further evaluation. Again, this is only a pilot program, so it will be a while before we know if this is technology that we will implement in the long-term.

Field testing

To the best of our knowledge, the prototype graffiti drone is the only one of its kind. We've used drones before in other capacities like bridge inspections and disaster response (flooding, landslides, etc.), but use for graffiti removal is new.

Our highway maintenance employees with Part 107 drone licenses are being trained to operate the drone. Mike and his crew will spend the rest of the year field testing the prototype drone in the Tacoma and Olympia area.

Legally, drones cannot be flown over active lanes of traffic, so the areas we are treating will be in closed work zones or managed with rolling slowdown closures while the drones are in use.

As they field test the drone, the team expects to make further improvements to the system.

This pilot program won't end highway graffiti – it's a constant struggle for our crews and law enforcement to address – but it's another tool in our toolbox. We are excited to continue exploring new technologies to keep our crews safer and make them more efficient.

Graffiti: A tale of two signs

By April Leigh and Tina Werner

Opinions about graffiti vary almost as much as the expression itself. It’s an art form to some and a nuisance for others. In the context of tagging along highways and bridges, graffiti poses many concerns for us.

Graffiti is illegal under Washington state law. It puts people in danger (those doing the tagging along a busy highway and our crews involved in the removal) and costs taxpayers thousands of dollars annually. It also takes away from other work we do to keep our transportation system in good working order like repairing potholes and guardrails.

We do our best to keep up with requests to remove graffiti, especially on directional signs and in areas that cause distractions for drivers. Unfortunately, our crews often report that a location is tagged again within days or even hours of graffiti removal.

Crews removing graffiti in the pedestrian/bicycle path above the Mount Baker tunnel in Seattle.

In February, graffiti was sprayed across two overhead directional signs on the off-ramp from southbound Interstate 5 to State Route 512 in Tacoma. The defaced signs posed a significant distraction for drivers and covered directions for traffic, so they had to be removed immediately.

These overhead signs on the southbound I-5 exit to SR 512 and South Tacoma Way had to be removed and replaced after they were tagged with graffiti.

These overhead signs are located along a very busy stretch of I-5 and have been repeatedly targeted. A temporary directional sign was moved to the roadside while maintenance crews started work on a fix. When all was said and done, both overhead signs had to be replaced and a catwalk removed from the sign structure to prevent future tagging.

Whoever vandalized the signs had to crawl across that catwalk to do it – endangering their life and the lives of everyone who passed underneath them.

Replacing signs – particularly overhead ones – is a timely and expensive task. In this case, the graffiti defaced the entirety of the directional signs, and they were not able to be salvaged.

How much does something like this cost? Our team is still calculating the final bill, but replacing both signs is estimated to be between $40,000 and $50,000. That includes labor, equipment and materials.

Crews use large trucks equipped with hydraulic arms and buckets to replace the overhead sign on the ramp from southbound I-5 to SR 512 and South Tacoma Way.

The cost of graffiti

Graffiti removal projects like this are paid out of our maintenance and operations budget. Our crews prioritize critical maintenance activities (PDF 187KB) like catch basin cleaning, snow and ice removal, mowing for sightlines and other work. The more resources we spend on graffiti removal, the less we have for this other work.

In the past two years, our maintenance teams have spent $1.4 million on graffiti removal. In the next biennium, we expect to spend even more to address the growing issue.

Graffiti vandalism on the rise

We’ve seen an increase in graffiti vandalism along our state roads over the past few years. Newly completed bridges, overpasses, walls, and other structures are often hot spots for these crimes as they offer a fresh blank canvass for taggers. Active construction projects with new or closed sections of roads also attract activity because there is no traffic there at night.

A section of a new wall along SR 16 in Tacoma before and after graffiti removal.

Crews often have to use special equipment to access the vandalized areas – like trucks with lifts to reach high places that would otherwise be used to maintain, inspect or clean state bridges. Using equipment like this also requires traffic control or a lane closure during daylight hours. This is a huge challenge when we’re also trying to keep traffic moving.

What about designed safe-graffiti spaces?

Some people have shared that they’d like us to allow for portions of our highways and other facilities to be safe-expression spaces for graffiti artists. Safety plays a big role in this effort along with consistent monitoring of the spaces for vulgar or offensive language.

We are aware and have been evaluating the innovative artist in residence program and how it could help address safe-graffiti spaces. However, we are currently in the middle of legislative session where bills have been introduced on this topic and we are awaiting hearing what the results are.

How graffiti removal is prioritized

While graffiti is a crime and a law enforcement issue, the cleanup is our responsibility and we do so as often as we can. We prioritize removing graffiti with vulgar or obscene phrases. As we are not a law enforcement agency and don’t have enforcement authority, we partner with law enforcement, but they must catch someone in the act of tagging to be cited for vandalism. Given that much of the tagging happens at night, this is a huge challenge.

We aren’t funded to have or hire specific-graffiti removal teams. It takes time and planning to coordinate a cleanup site. We try to roll this work into other projects occurring in the same area to minimize disruptions to drivers, and work with neighboring cities and counties on prioritizing large sections that draw noticeable concern. You can report highway graffiti online too – and we share that directly with our crews to address as time and resources allow.

We’re often asked why we don’t use our traffic cameras to help law enforcement capture taggers in the act. Our traffic cameras only provide the most current snapshot image. We don’t record footage from them as that would require a significant investment to support storing video from more than 600 cameras statewide. Law enforcement must catch someone in the act of vandalism to potentially arrest a person on state property.

Crews removed graffiti from this I-5 sign near Marysville at 88th St NE.

Bottom line: There’s always been, and likely always will be graffiti. Along with law enforcement, we will do the best we can within our resources to try to keep up, but ultimately it’s up to those committing the crimes to stop putting themselves and others at risk.