When That Child in the Street Is an Optical Illusion

Let’s say you live or work in an area where there are a lot of vulnerable pedestrians – kids, maybe – and a lot of cars as well, and that the cars habitually drive too fast for your taste.

What do you do?

Maybe you put up some warning signs, or speed bumps, or try to get the police to strictly enforce the speed limit.

Or you could try this:

According to the Star, this is a “heat-plastered decal” installed on a street near an elementary school in West Vancouver. For oncoming drivers, it creates an optical illusion that there’s a little girl chasing a big pink ball in the middle of the street:

The decal on the road appears to drivers as they approach the image from 100 feet away, the sweet spot is between 10 and 50 feet away when the girl appears in 3D for a brief second. … The $15,000 decal was paid for by Preventable.ca, a non-profit organization that works with the BCAA Traffic Safety Foundation, WorkSafeBC and other groups aimed at preventing accidents.

The goal is obviously noble: to cut down on traffic injuries and fatalities of children. But, as with the fake speed bumps in Philadelphia, one can imagine a host of unintended consequences:

  • After you’ve seen the illusion once, does it lose – or negate – its effectiveness? Do you assume that a real kid in the street is just another decal?
  • A driver who sees the decal for the first time and slams on his/her brakes may increase the chances of a rear-end collision — kind of like the red-light-camera effect.
  • What happens if a driver responds to the illusion by driving off the road and hits a real person, or has a heart attack?

It should be noted that the decal was removed after one week. It was an experiment, a stunt, designed to create awareness around the school. It easily did that, and beyond.

(HT: Brad Garland)


None of the "unintended consequences" sound realistic to me after watching the video - drivers see that there's something on the road all the time, it just gradually turns into a lifelike image as they approach the right spot.

Ian Kemmish

If you want to surprise the driver into remembering that there's a school about and it's the start of term, then the low-tech approach may be better:


Nobody is going to forget a horse painted as a zebra in a hurry.



That's assuming that drivers are as singly-focused as viewers of the video. In reality people will be distracted, looking elsewhere, talking to another person in the car, etc. It certainly wouldn't happen to every single driver, but in my opinion it's not at all far fetched to imagine that a distracted driver first glancing at the decal while it's in the sweet spot could panic and cause real harm to themselves or others.

And let's not pretend that we can avoid distracted drivers, no one can focus on the road 100% of the time, our brains just don't work that way (and because obstacles don't only approach from directly in front of us, that type of tunnel vision would be dangerous).

Matthew Huggins

Throw away your civil engineering codes, narrow the streets and line them with on street parking.

Eric M. Jones

I'd worry that these might teach you to ignore stuff in the road.

In the Yucatan they use speed bumps "Topos" with a warning sign that looks like two breasts. Apparently you can install your own local topos if you think it is needed with or without warning sign.. You can spot the topos and slow down 99.7% of the time. There are tens of thousands of them.

The 3/1000 that you fail to see and react to will really teach you religion.

Ask me how I know....!


I think it would distract me from actual happenings around me (perhaps a kid or dog or car), and I am enough of a geek to go around the block to see it again, and focus even more on it - what does it look like from the other direction... I akshully :-) think it might just be an accident waiting to happen.


Yay! Compliance through deception.


How about the unintended consequence of increasing the amount of traffic in the area due to the unique nature of the forced-perspective artwork? Can't you imagine the traffic would increase in the area as word of it got around - much like a unique lighting display would attract more cars to a neighborhood during the holidays.

Raven Keller

Is there really a way to force drivers to pay attention? It's a decision that people have to make, and here I echo Brett - even the best driver can't pay attention 100% of the time.
It is natural for us to grow used to input and to stop paying so much attention to it- our bodies stop responding to the sensation of jewelry and wristwatches after a bit so as to focus on other sensory input.
The majority of accidents happen within a few miles of a person's home- it is very familiar, they feel comfortable, and are not expecting new input. Every day that they have driven past the elementary before, the children stayed on the sidewalk. They went 40 in the 25 mph zone and it was always just fine.
Driving inside a closed container, a bit separated from the passing world - they have to decide to pay attention or the sensation of driving has to change enough so as to keep them aware.
Perhaps some sort of smart technology would help. I am generally not in support of smart technology telling a person when to stop eating* or what products to buy, but in a situation such as driving, in which your actions can directly harm others, then I could imagine it being helpful if done correctly. That would of course require purchasing the equipment or placing it in all new cars, and then expecting the car owner to maintain it.
*one of Stephen Dubner's podcasts makes mention of the $2.50 health care cost created each time an American choses a burger over a salad, but that's still indirect. Wow, I feel like a suck up.

What happened to speed bumps?

But really, I wonder what sort of strange image the people driving the opposite direction are seeing...

...and how the production of this decal reached $15,000!

Here's to biking



Said this on another forum last week that linked to a story about this decal:

This is an idiotic idea.


Given the amount of idiots one sees driving 10 under in the passing lane, and the number of idiots found tailgating other motorists in parking lots, any idea that grabs the drivers attention to the road and reinforces safe, correct driving speeds, however idiotic, is a good thing.


I would think that parking a police car, or even a car that just looks like a police car, near the school would have the same effect without the potentially dangerous repercussions. People would automatically slow down to avoid the ticket, but wouldn't slam on their brakes.

bert seyfarth

Matthew Huggins go to the front of the class.


I admire the ingenuity. But this has "unintended consequences" written all over it.

A guy's driving down the street, not breaking the speed limit, but sees this and makes veers into oncoming traffic. Or how about seeing it at night--in a rain storm?

SPEED BUMPS. They still work. If you have to put one every 20 feet, do it.

Better yet, park a police car (empty?) along the road, flashing lights on. That'll cause people to be a bit more careful.

Ken Arromdee

"The majority of accidents happen within a few miles of a person's home"

I suspect that this happens because the majority of driving happens within a few miles of the driver's home, so it means nothing.


Yeah, this is definitely an example of someone not thinking an idea all the way through before deciding it's a good one.

Think about it. If you are supposedly so distracted that you wouldn't see a REAL kid playing in the street, then why would you be expected to spot a fake one?

The last thing we need in the world of traffic engineering is something else to make us slow down or stop suddenly when there's no reason to...

Joshua Gold

I remember seeing many years ago a form of speed control in which driving on the bumps on the road led to a pleasant melody. The catch was however, that if you drove over the speed limit the pleasant sound would turn to a more irking tune, softly nudging you to bring down your speed. Here is an example of the musical road http://www.youtube.com/watch?v=RLNfN6-eA0g


Count me among those who are horrified and would support banning these things. Previous posters have already pointed out that possibility that motorists will cause more accidents by swerving or slamming the breaks to avoid hitting this "child".

The real danger to me is that we are conditioning motorists to ignore the child in the road. How many people will get used to driving over this thing and then not hit the breaks when a real child steps in front of their car. Drivers need to have that instinct to slam the breaks under these circumstances.



I prefer school zones that have a blinker that flashes when the school zone speed limit is in effect.

I drive past the same school twice a day every day all year & unless there is a big yellow bus in front of me or a line of traffic piled out to the street, I really don't know whether the school is in session that day or not. Unless there is obvious activity I assume that the regular speed limit applies.

Conversely I dislike schools that have crossing guards on a power trip screaming at you when you are going 15 mph and there are no pedestrians. (To be fair, I've really only seen this at one school.)


is it so unreasonable to expect an individual with a driver's license to JUST BE RESPONSIBLE and ATTENTIVE and not run over children or other pedestrians in the street?

forget the artwork.

just add a speed bump across the road at the very place any pedestrian is ever hit.

that will make people slow down, and knowing WHY the speed bump is there might help those drivers continue to be responsible and attentive.


The answer to so many problems seems to be: smaller cars going slower.