Traffic light systems are easy for hackers to override in fiction. This can be done in a non-malicious way to show off a hacker's (or AI's) skills at breaking into a network, or for the more pragmatic reason of letting the hacker and his teammates make their escape from a crime scene via car while their pursuers are stuck in the resulting traffic jams. Spies and criminals may use traffic light hacking to help them escape from a caper or heist.
While 2000s-era shows often depict a brilliant computer wizard in a Hacker Cave far from the actual traffic lights, in older examples, the system might be hacked by getting into the mechanical timing gears on the street level. While changing traffic flow is the main reason for hacking lights, occasionally, it may be done to send an SOS. Bonus points if all the lights glow green (or any given colour), as opposed to just the green ones.
A more dangerous variant is hacking the signals that coordinate train movements, or the warning lights where train tracks and roads intersect.
With the increasing shift to the Internet of Things, in which city systems and infrastructure is linked into the Internet, hackers being able to break into city transportation systems is Truth in Television.
Examples:
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Anime & Manga
- Fujimaru of Bloody Monday did this from his laptop to stop the terrorists from escaping with his kidnapped sister (Chapter 12).
- Ghost in the Shell: Arise: "Ghost Whispers", the hacking of traffic system electronics including the lights are done by rogue JGSDF Ranger soldiers in order to prove that they are serious when they want their imprisoned CO freed of false charges.
- A case where the lights are messed with more directly than actual hacking, Splatoon: Squid Kids Comedy Show has a gag where a thief goes across the road just before the lights turn red, blocking Hit and Maika from chasing him. Hit decides to shoot green ink at the lights, technically turning them all green, and therefore allowing him to cross. Unfortunately, this also means the other street had green lights too, leading to a vehicle slamming into him.
- The technopath Satsuki Yatoji from X/1999 is introduced hacking a street light from her cellphone while riding a bicycle.
- Done at the start of the You're Under Arrest! movie as part of a terrorist plot created by an ex-Tokyo Metropolitan Police officer in order to prove his work on how to cause a terror attack on a country with first world standards.
Comic Books
- In a Spirou & Fantasio short story, Fantasio equips an old car with a device allowing him to remotely control the traffic lights so that they are always green for him. He later gives it to an oil magnate who, being colourblind, misuses it and turns all lights red for him.
- In one Underdog comic, Riff Raff takes over the city's traffic control centre and uses the traffic lights to create havoc so his gang can commit crimes. In attempting to fix the problem, Underdog accidentally ends up sending every car on a one way trip out of town.
Film — Animation
- The Bad Guys (2022): This is how Ms. Tarantula is introduced in the opening sequence — hacking the traffic control system to turn the lights green, clearing the road for Mr. Wolf and Mr. Snake to escape in the getaway car, then changing the lights back to red to cause pileups at each intersection, hindering the pursuing cops.
Film — Live-Action
- One of the first things we see in The Dungeonmaster note is the techie protagonist jogging while his computer changes the traffic lights in his favor.
- In Ghost in the Machine, one of the Digitized Hacker's attempted murders involves hacking traffic lights to cause accidents.
- Older than You Think. This was part of the ploy in The Italian Job (1969) — by switching the computer's big tape reel with a phony one made by the crew's computer genius, Professor Peach (played by a young Benny Hill), they make Turin's traffic system go haywire, creating a massive traffic jam which the gold-heisting crew can then escape in their small and super-maneuverable Mini Coopers.
- Used again in The Italian Job (2003):
Lyle: "You'll... never... shut down... the *real*... Napster." [At the traffic control center, the message "YOU'LL NEVER SHUT DOWN THE REAL NAPSTER" appears across all of the video monitor screens. The scene changes to various clips of gridlock across the city]
- Incidentally, where the original film causes all the lights to go haywire and show bizarre colors like red and green or nothing at all, causing traffic to grind to a halt all over the city but probably not directly harming anyone, the remake does so by having Lyle shunt all the lights to red, then change strategic lights to green to stage accidents to further compound the gridlock.
- In Live Free or Die Hard, the bad guys are able to shut down traffic and other utilities as part of their master plan.
- In Speed Zone, Lea and Margaret do this as they're leaving Washington. After coming to a red light, Margaret uses her computer to turn it green, then turns it back to red as the other racers reach the intersection.
- In Superman III, the supercomputer causes the figures in a Walk/Don't Walk sign to animate and fight each other.
- In Taxi, rather than hack, the protagonist has multiple copies made of a key that makes a single traffic light go red. His gang uses them to keep ordinary people out of the avenue where they lure the baddies for the big chase scene, reducing the risk of accidents.
- Once they are given the Handy Remote Control, the trucker brothers in Think Big try to do this while they rush to their destination before the deadline closes, but it takes a third try before they get it right.
- In Where's Willie? the titular Child Prodigy invents a computer that can hack into almost anything, from actual traffic lights to the clock at school to locked doors.
Literature
- Played with in Masked Dog by Raymond Obstfeld. The assassin doesn't hack into the traffic lights but rather uses his super memory skills to memorize their patterns, then manipulate his target into position by acting as a road rage hoodlum.
- The killer in Mr. Mercedes has a home-built device that can change lights, although he later muses to himself that he didn't actually need it to make a getaway after his initial crime.
- William Marshall's Yellowthread Street novel Roadshow is another pre-internet example, in which a gang of criminals deliberately cause gridlock in Hong Kong by a mixture of physical sabotage of traffic lights and computer sabotage.
Live-Action TV
- In the Agents of S.H.I.E.L.D. episode "Girl in the Flower Dress", Miles (a Rising Tide hacker) reveals he set up this kind of hack ahead of time in his city's traffic computers and he makes all the lights of an intersection green during a chase to get away from Coulson. Unfortunately, the very second he pulls over to catch his breath, Coulson is there to arrest him.
- Alias: In one episode, Marshall is nearly foiled by the fact that the website is in German, but Jack is there to lean over his shoulder and tell him which button means "red."
- In The Blacklist, the kid pretending to be the feared hacker Ivan hacks the streetlamps in his hometown as part of an attempt to impress a girl.
- In CSI: Cyber, white-hat hacker Daniel Krumitz is asked by the FBI SAIC Simon Sifter to cause a traffic tie-up to slow down a suspect. He tells Krumitz to turn all the lights red to stop them. Krumitz says turning all lights green is actually more effective at stopping traffic (and he can do it), but needs to get specific permission to do (after all, he's a white-hat hacker). Sifter gives him the specific go-ahead and the traffic gets tied up throughout the area.
- The Flash (2014): In "The Sound and the Fury", Cisco uses his super hacking skills to slow down the Royal Flush Gang by turning the lights red during their getaway.
- Intelligence (2014): One episode has Gabriel use his chip to change the traffic lights to allow him and Riley to catch up to a suspect.
- Lie to Me: the episode "Saved" has an interesting variation of this trope. Cal Lightman finds that a particularly heroic paramedic saves so many lives because she knows where the accidents will be. That's because her brother hacks into traffic lights and purposely causes deadly accidents.
- In a MacGyver (1985) ("Thief of Budapest") episode, Mac "hacks" the stoplights in a town in Europe to help him make his getaway, by putting fragments of a credit card in a timing gear.
- NCIS: One Victim of the Week uses the traffic lights to send an S.O.S. from the chamber where he's imprisoned. He dies before he's found, though.
- Probe:
- "Computer Logic": An unknown force causes the traffic lights to malfunction, causing the death of David Hofstadter because the intersection showed green for all lanes and a truck hit him.
- "Computer Logic, Part 2": Crossover is able to manipulate traffic lights, indirectly killing David Hofstadter because the intersection showed green for all lanes when the truck hit him. The lights are also used to communicate with Austin in morse code.
- Spooks: In the episode "Outsiders" the Villain of the Week has invented an algorithm that enables him to hack into any computer system, and one point changing traffic lights to cause a traffic accident among those investigating him.
- Supergirl (2015): In "Solitude", Indigo turns every single light in National City green as a distraction so she can escape from Supergirl.
- Ultraman Ace: One episode featured a Monster of the Week called Signalion whose power was to make traffic lights go haywire, which the alien controlling it used to cause mass chaos in Tokyo.
- In The X-Files episode "D.P.O.", the title character does this by fiddling with the electronics of the traffic lights telekinetically, because he enjoys watching cars smash into each other.
Tabletop Games
- Champions supplement C.L.O.W.N.. When the founding members of C.L.O.W.N. were just teenagers, one of their "pranks" was to cause all of the stoplights in town to turn green at the same time. The writer of the supplement apparently didn't realize that this would cause cars to crash into each other in the intersections, leading to mass injury and death. This is particularly odd given that the group is conscientious about not causing serious damage or injury with their pranks, to the point of expelling one of the founding members for violating that standard.
- The d20 Modern supplement "Urban Arcana" includes a spell which changes red lights to green in the path of the player's vehicle.
Video Games
- Grand Theft Auto V: Part of the "subtle" option for the Union Depository heist involves your hacker manipulating Los Santos's traffic light grid to keep Merryweather away from Michael and Trevor. Notably, you can't just set the lights to whatever you want; you can only toggle which street has the green/red light at each intersection.
- Mega Man Battle Network 1: in Colorman.EXE's scenario, he hacks into the traffic lights—causing them to turn green in all directions, which in turn causes the automated self-driving vehicles in the city to collide with each other. Lan and MegaMan.EXE have to counter-hack the traffic lights (putting them into an all-red failsafe mode) in order to stop this.
- Super Solvers: Midnight Rescue features a story about Morty Maxwell using his magic powers to mess around with the traffic lights so they were all the wrong colors and sprouted an umbrella, too.
- Watch_Dogs: Aiden Pearce is able to do this, as seen in the page image. It's used to cause pileups to help escape from pursuers - although it does also get used against him later on in the game to block him.
Western Animation
- In Count Duckula, there was one episode with an intelligent and slightly evil computer, who invites Duckula to play a game about traffic lights. It turns out it controls real traffic lights.
- In the The Penguins of Madagascar episode, "Go Fish", Kowalski hacks the city's traffic lights in order to stop a fish delivery truck so that the other penguins can steal fish from it. Unfortunately, he accidentally licks one of the wires when he thinks about fish, causing the light to turn green and the fish truck to get away. This one is at least a bit more realistic, as they're fiddling with the wiring of the lights, rather than Rapid-Fire Typing from a remote terminal.
- In Spiderman The Animated Series, the Hobgoblin gains access to the Kingpin's computer console, and raves about the information he'll be able to control. The first thing he does is create traffic chaos.
- Teen Titans Go!, "Hey, Pizza!": Beast Boy and Cyborg do this on the tower mainframe in one of their attempts to slow down the pizza delivery man in hopes of getting free pizza. It doesn't work.
Real Life
- Traffic lights are occasionally hooked up to the internet as a few
articles show. Some cities’ lights can sort of be hacked via other means besides the internet, thanks to a system known as Opticom which allows emergency vehicles to change the lights red to halt traffic while they speed through, but it's surprisingly less "high-tech" than you'd imagine. It essentially works like the remote control of your television, with the vehicle flashing a strobing infrared (and sometimes visible) light at a receiver mounted on the traffic lights, and this actually wouldn't be difficult to obfuscate with the proper gear and a bit of know-how. The real problem though is be that this system sends an alert to a central station when tripped so if there are any surveillance cameras on or around that light, or a witness who watched the one car speed through the all-red intersection, consider yourself busted.
- The electronic road signs that light up and display information about road closings and other problems can often be easily broken into and made to display arbitrary text.
