Road Sign Hacking

We’ve all seen these on the side of the road and wondered how we could change the message. It turns out that it is actually pretty easy. There’s a keypad inside for programming that is often still set with a default password of “DOTS”. Even if the password has been changed, you can reset it right there pretty quickly. We shouldn’t even need to warn you that it is illegal to tamper with these, so unless there really are zombies ahead, you probably shouldn’t mess with it.

[via Neatorama]

158 thoughts on “Road Sign Hacking

  1. Sweet, although if you are planning to do this hack, even though it is illegal, plan to do it quickly, I bet this spreads across the internet pretty fast and the company that makes them will find out and send some info to the owners.

  2. Awesome hack! Only do the ones that have a ‘detour ahead’ or some such trivial bulls***. Don’t mess with the ones that are already displaying an important message…

  3. Used responsibly, this could brighten many a very bored commuters day!
    I would like to think that those intelligent enough to do the hack would be intelligent enough not to replace “danger (insert hazard here)” with anything, inane or otherwise :)

  4. I’m a frequent reader of this website and absolutely love it…but you know, as an employee of a state Department of Transportation, having worked in Construction all last summer, I’d really, REALLY, like to advise would-be hackers to NOT mess with these signs. Let me explain.

    Drivers are really, really, really damn stupid. Besides Construction, I’ve also worked on plans for traffic control and notification and we throw every freaking thing imaginable, short of a personal attendant for every vehicle driving through a construction zone, to alert drivers to construction and detours…more than you’d think simply don’t pay attention and then get pissed at US because they don’t know what’s going on. Furthermore, those signs are used to warn drivers about work being done, especially when the work is not behind protective barriers. When you’re standing next to live traffic running at 70MPH and the only thing separating you from the Almighty is the driver not being a dumbass, you’d have a much bigger appreciation for PCMS (portable changeable message signs) locations warning people about your ass out on the jobsite. In addition, PCMS warn drivers about changing road conditions or detours. Many drivers on interstates aren’t familiar with the areas, and those smart enough to actually read the signs need PCMS messages to let them know about a traffic shift or a detour. Have you ever seen an 18 wheeler accidentally trapped in a residential area? What about one that’s trapped in a downtown grid because traffic is moving one way and the area is too narrow and not tall enough to accommodate the truck and trailer, during morning rush hour? I have, and it’s not fun to deal with.

    There is no other hack I’m aware of chronicled on this webpage that runs the risk of putting anyone in danger except the person doing the hack themselves…this hack, however, could result in fatalities, and I’m not being the slightest bit over-exaggerative. Please don’t mess around with PCMS!


  5. I agree with Frank, 100%. That said, down here in Florida just outside of Daytona last year just before one of the major races, one of the pcms was hacked to say “Nascar Sucks! Go Home!”… I laughed and thought “How bad would it be if that really hit somebody’s funny-bone”… could be a new kind of “deadly joke”… the incident made the Orlando paper as well.

  6. Word of warning… These signs can also be controlled and monitored remotely. DOTs will prosecute for vandalism. How do I know this? I work for a State DOT. I would not do this.

  7. at the risk of incriminating myself in a fraudulent bridge collapse about 6 years ago I have been doing this with a group of my late night techy friends since the first time i bought a 2600.

    It was one of the first articles i read and i went straight home called buddies and gathered dark clothes and daddy’s bolt cutters.

    that year home town had a number of mysterious pokemon catastrophes, bridge collapses and blinking middle fingers (we were young and short on actual imagination from all the video games)

  8. Meh, I have a 60 minute commute every day, and I would love to see a sign that says Zombies Ahead…

    A couple summers ago they resurfaced the street and for about 3-4 weeks ahead of time they had one of these signs up saying “Road construction starting in three weeks”. While messing with a sign that is in a live construction zone would be a very bad idea, and I would be strongly against that, I think changing a sign that is warning about future construction would not be so bad.

    However, this makes me very glad that I do not work with the DoT or with any road work crew…

  9. Now that this is published, and requires nothing other than typing in a default password, this hardly qualifies as a ‘hack.’ Play around with these at your own peril, but know this. You will not be respected for such an oldskool prank. Especially now that you can find a HOWTO with Google. I’d say this now qualifies for publishing in 2600!

  10. Funny, but a bad idea from the public safety standpoint. Would be better suited to make a zombies ahead sign (assuming you do not live in Boston). Or hack adverts that use a similar system. I just cannot condone road sign shenanigans. As the chap above me stated, many sheeple are just to dumb for you to mess with their do not hit guys in bright orange vests signs.

  11. The ones in colorado mostly use one of 4 basic 4 letter passwords. if they dont, its because they tried to give them individual 4-digit passwords at some point, which no one could then remember because they move around so much. To deal with that they just wound up writing the sequence on the inside of the access cover. not real secure. Have fun and remember safety is a joke!

  12. as for the the actual use of a odd message it might help people pay attention to the signs following it just to see if there are anymore funny things and in turn they actually realize that there are people working up ahead. eg have 3 of those signs setup 1st with a real message that most ignore, 2nd with a something like the zombies to get their attention, and then on the 3rd have a real message again so that they actually pay attention to the workers… who knows it might actually be helpful but then again like it was said earlier… sheeple
    but still safety first!

  13. Replace it with danger watch for monkeys in suits.
    Also apparently from these posts it seems people who work for the state are all assholes and humorless pieces of shit.
    But seriously if it has a warning for safety at a construction zone don’t mess it.
    It may not cause an accident but some nanobrain will blow things out of proportion.
    If it’s some nascar advertisement or some other BS sure knock yourself out.

  14. I use to drive a Semi Belly dump hauling HOT Asphalt for these construction jobs and I would hate to count the number of DUMBASS DRIVERS that tried to PUSH 80,000 to 200,000 lbs (Depending on what state laws were) of semi through the construction site FASTER and then follow me OFF THE ROAD INTO THE CONSTRUCTION TRENCH 2 inch drop off to a 10 INCH DROP OFF! That idiot did and stopped all traffic and construction until a tow truck (Medium Duty $$$$$) pulled his CLASS “A” motor home out of the trench (With a twisted frame) 2 hours later.
    STUPID driver was about 6 inches off my stinger and didn’t see where he was going just pushing me out of his way as I was slowing him down.

  15. This reminds me of one I saw a few months ago that said “Ashley, will you marry me?…..Just kidding It’s over!!” no joke. I about drove off the road when I saw it. It was gone by the time I got back around that direction so I never got a pic of it.

  16. “Also apparently from these posts it seems people who work for the state are all assholes and humorless pieces of shit.”

    You really don’t get it man…when 80,000 pounds of truck is barreling by at 70MPH, you’ve closed off the slow lane and you have men working in it, at 6am, with only cones up, do you really think it would be a good idea to take away one of the main ways to communicate to the driving public that you can expect a lane closure and that men are working just ahead?

    you’re the one who is an absolute asshole. i’m not humorless, but if i’m personally responsible for the lives of the men working, i don’t find it funny when stupid idiots fuck around with safety measures put in place largely because of horrible accidents we’re trying to prevent from happening again.

    and no, it’s not someone blowing things out of proportion being concerned about safety signs changed. until you’ve worked out on a jobsite, you just won’t understand how many hazards there are and how many we’re minimizing for the workers and the traveling public, including your ungrateful and stupid ass.

  17. I doubt there is a high risk of widespread abuse due to this article. This exact information was published in 2600 magazine and subsequently all over the internet years ago, and there are still very few incidents.

    but if the hole is so worrisome, then maybe someone should plug it. Just a thought.

  18. What’s next to be posted ,that can KILL people : a nuclear central access code hack ? An airplaine network hack ?

  19. don’t post these things is not the correct response. As jesse said, this was in a 2600 magazine and this info has been around for years. If you give a damn – express concern, explain why, address the root of the problem by taking it up directly with your state DOT. Suppressing knowledge of a known problem is the most dangerous thing you can do.

  20. There is a sign about a block from my house that says “buckle up…. and don’t speed… or you’ll get fined”

    I think it’s perfectly harmless to mess with this message.

  21. @bob, you sir are the reason I hate corrections officers. (bare in mine I have no problem with “cops” and my own twin was a corrections officer) You have men, in a cage, who you are in charge of watching, many of those men are long timers who want nothing more then to get out and move on (bare in mind i have done long stints) and you would suggest lying about what i might have done on the outs and cause me to be harassed, beaten or raped???? sir if i knew what department you were employed with i would send your captain a link to that post with a letter explaining my disgust.

  22. Man.

    At least when April Fool’s day comes, road sign hacking is available to public.

    But, wouldn’t it be best that the pic shown on the post that “Zombies Ahead” would be for halloween or something so when kids see it, they become scared?


  23. “anyway, part of your traffic management plan should be to check the signs each morning – so whats the damage?”

    it is true that all roadsigns are checked at least on a daily basis (at least on my projects, they were, but we were squared away). that’s no reason to say the issue is now non-existent. that’s like saying you’ve left a loaded revolver within a toddler’s reach, but since they have such poor motor control it’s practically impossible for them to fire it – so what’s the damage? that sort of logic is just stupid.

  24. “don’t post these things is not the correct response. As jesse said, this was in a 2600 magazine and this info has been around for years. If you give a damn – express concern, explain why, address the root of the problem by taking it up directly with your state DOT. Suppressing knowledge of a known problem is the most dangerous thing you can do.”

    so you’re telling me i’m wrong and should do what you’re saying, not just saying “don’t post these things”…well, i do give a damn, i have expressed concern, and i’m calling my old boss tomorrow to give him a heads up. i don’t see what the point of your post was, since you’ve described what to do after i’ve done so. and don’t think you’re brilliant coming up with your “don’t suppress the truth, that’s more dangerous” nonsense. you sound like a hippie and an idiot. this situation isn’t about “suppressing truth”. it’s about not openly giving out information on a hacking website that can cause harm to anyone but the person thinking about doing the hack. if someone wants to mess around with huge capacitor banks and leyden jars from hell or arc welders or jacob’s ladders, then fine. have fun, and if you get hurt it’s on you. i don’t see you posting your home address, dob, and ssn around here, even though that’s “suppressing truth” in the same way according to your logic.

  25. This is coming from a guy who arranges his bosses desktop icons to look like a dick…

    Don’t mess with roadside warning signs. If you do…I hope karma kicks you squarely in the ass. Using a toaster oven to resolder, ok. Hacking up a security system for your apartment, okay. Putting peoples lives in danger for childish reasons, not okay. IMO.

  26. @ gravitus

    Ha Ha thats the funniest thing I have heard in the last week !

    Anyway, I don’t really like this Idea. Those signs are there for a reason. Changing what they say could result in death.

    Just think about that, Imagine if someone died in a car crash because of you changing the road sign to “zombies ahead”

    Well, I don’t think I could live with myself !

  27. I think the phrase “Zombies Behind” would be more likely cause a crash. “Zombies Ahead” would only be dangerous if there were actually workmen on the road…since running over zombies is, imo, fair game.

  28. Well I found the article funny, always wondered what kind of system those things had security wise.

    I was just content reading about it and going on my merry way for the rest of my life, however thanks to Frank I have a new mission in life.

    I’m going to personally screw up every single one of these signs I find with “Frank sucks” and “Fuck Frank” until he gets fired or manually retired from his job.


  29. “I would like to think that those intelligent enough to do the hack would be intelligent enough not to replace “danger (insert hazard here)” with anything, inane or otherwise”

    How’s the weather on Tralfamadore?

  30. Frank, seriously, these guys are trolling you. Most of the people that read this site have somewhat of a conscience. I don’t think that anyone is going to change a sign that says “please slow down, men working” or “let em work, let em live” to “distraction, 100 points for the white guy”. I agree that the information should be public so that everyone knows about the problem. Just like when security experts find a critical vulnerability in windows, make it public so everyone knows, then release a fix to prevent script kiddies from exploiting it. Same case here. If everyone knows about it, then the DOT will have to establish some sort of password requirement and schedules. And besides, if everyone knows about it, then it’s everyone’s fault if it doesn’t get fixed or causes problems.

  31. hmm… one of these signs with a solar panel has been pretty much abandoned on a highway near me… it was programmed to say “drive safe” and has been there and said that for the last year and a half. It’s half burred in a snow bank right now and for a few weeks it didn’t work because the solar panel was covered with snow…

    I’d never consider using this hack on a sign setup to help protect road workers… but I’d say this abandoned sign would be the perfect candidate for testing this out.

  32. “that’s like saying you’ve left a loaded revolver within a toddler’s reach, but since they have such poor motor control it’s practically impossible for them to fire it – so what’s the damage? that sort of logic is just stupid.”

    Actually, I think that avoiding talking about such an obvious and stupid security flaw is closer to your analogy. It’s a very poor analogy, but still. perhaps it’s like leaving bullets in the gun and saying, “hey don’t tell that kid how to fire it”. Still a VERY poor analogy, but better use than your first attempt.

  33. I used to work for a manufacturer of traffic signs (the big, honking stationary signs) as a software tester. As a tester, I had access to the database containing the dial-in numbers for a hundred or so signs. I always wanted to change them all to something funny (the messages were never important), but I didn’t have the balls.

  34. Usually they place other non electronic signs along with the marquee sign.
    You usually see warning signs about 1/4 mile before entering the the construction site.
    If the only warning is the marquee sign then someone is doing something very wrong.
    If you don’t want them messed with then lock the thing but still there should be orange warning signs as well since these can’t get dead batteries etc.
    BTW frank everyone trolls you because you make yourself a good target by provoking them farther.
    Though I wasn’t trolling you and I said I would never mess with a sign that has safety warnings even though if things were done right there would be a half dozen other warning signs and a mess of traffic cones telling everyone this is a construction zone.
    I was trolling bob because he is an ass.

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