Zombies have taken over the streets of Seoul.
No, it's not a scene from the latest Korean summer blockbuster, "Train to Busan," where the living dead take control of a speeding train.
Instead, these are South Korea's smartphone zombies: distracted walkers wandering the city's sidewalks and wide boulevards, seemingly oblivious to everything except the latest text, alert, or notification on their phone.
And in one of the most wired countries on the planet, where more than 80% of people own a smartphone, you don't have to go far to find them.
Whether you prefer the term mo-zombie, smombie, or the cringe-worthy petextrian, it seems everyone is doing it.
"I almost got hit by a car while using my phone crossing the road," says 24-year-old Shin Ji-won.
"I didn't think it was such a big deal, so I keep texting while walking...Maybe I don't realize how dangerous it is."
Seoul's attempts to stop the zombie apocalypse
Seoul's Metropolitan Government says the number of traffic accidents involving smartphones have tripled over the last five years.
The data doesn't specify how many incidents involved pedestrians, or how serious their injuries were, but the number is large enough for the government to take action to raise awareness, says Kang Jin-Dong, the city's head of Transportation Operations,
At five of the city's busiest pedestrian areas, there are new road signs aimed squarely at those on the sidewalk.
"Be Careful of Smartphones While Walking." reads the text below an image of a smartphone-smitten pedestrian bumping into a car.
And sidewalk stickers that could be mistaken for no-smoking signs carry a similar message: "Walk Safely."
Kang admits the six-month pilot project, which costs about $33,000, is a work in progress.
For example, most people seem not to notice a signed crossing near Seoul's City Hall, being busy staring at their screens instead?
"Perhaps the signs should be bigger so they are more noticeable," says 33-year-old Kim Young-il," a walker-texter who is unabashed about his habits.
"I do think it's a good idea," says Shin Ji-won. "But I don't think they are really effective. I think they should come up with different ideas."
Kang says transport officials are incorporating that feedback into their plans to expand signage across the country next year.
How other cities tackle the problem
Seoul isn't the first city to try to address to get distracted walkers to look up.
In Augsburg, Germany, near Munich, pedestrians crossing the tram tracks are warned by a strip of blinking red LED lights mounted on the ground.
In 2014, a theme park in Chongqing, China painted "smartphone lanes" on 30 meters of sidewalk: one side for non-texters, and the other for texters, at their own risk, of course.
And then there's the tiny town of Rexburg, Idaho which passed a law in 2011, slapping a $50 fine on anyone who texts while crossing the street.
Addicted to iPhones?
"Research shows about 15% of smartphone users in South Korea are addicted," says Hyun-Seob Cho, a psychologist and Professor of Addiction Rehabilitation at Chongshin University.
Some of the warning signs you might be addicted, Cho says: feeling like your phone is an extension of your body, and getting nervous when you don't have your phone.
One of most extreme examples: a man who insisted on bringing his smartphone everywhere, including into the shower.
Cho says the trouble with smartphone addiction is there's no easy fix, because it's not realistic to ask someone to go cold turkey.
Instead, she says, people need to exercise a little self-control, and be willing to delay the instant gratification that comes with every text, tap, and swipe, if only for a few seconds.
"I think I am a smartphone zombie, and I think I should change," says Shin Ji-won, a nurse. "But it's not easy to put down the phone from my hand."