When I first heard of What3Words, I thought it was quite a neat idea but was put off by it being a closed, proprietary system. I became a bit concerned when emergency services started adopting it, and it’s now become clear that the system is quite seriously flawed.

We have this Keswick Mountain Rescue Team report:

For some unknown reason the W3W reference positioned the casualty close to the A66 near Braithwaite. Fortunately PhoneFind technology was used and a grid reference confirmed the location as on a path between Green Gable and Base Brown

W3W claim that similar sounding locations will always be a very long way apart. Some of the people I follow on Twitter have been digging into (and disproving) this claim, and someone has now found this pair:

disbanded.measure.snapper – next to the A66 near Braithwaite

disbanded.measures.snapper – near the path between Green Gable and Base Brown

Now we don’t yet know if this is actually what caused the confusion, but it’s quite a coincidence.

Obviously being a closed system, it’s quite hard to know how the location names are calculated, but some epic sleuthing based on information disclosed in their patent has shown that a flaw in the algorithm means that these kinds of confusable “plural-pairs” within a short distance of each other are common (full gory details).

There’s a simpler summary of the problems here: What3words is not suitable for safety critical applications.

W3W haven’t showered themselves in glory over this. They’ve continued to peddle the disproven 1 in 2.5 million stat, and have threatened to sue another security researcher who posted links to an open source implementation of their algorithm – although it looks like they may have now realised they were invoking Streisand with that one.

I always thought it’s biggest strength was it’s marketing team.

Yep I reckon your right ,it sounds a good idea but if you need the phone to give you the 3 words it may as well also send your gps location, so why bother with the whole 3 words fandango.

Yes it’s one of those things that when you first hear about it you think “hmm, that’s kind of neat” but once you look into the nuts and bolts and potential flaws it’s not really a sensible solution for any problem that I’m aware of.

My wife was trained on using W3W as a call handler for the South West Ambulance Service. Apparently protocol is to spell back the location reference to the caller and confirm, and then confirm the location that W3W comes back with on the call centre system with the caller. Obviously then if it’s miles out then the caller would re-check the reference and go again.

She concurs it’s not a perfect system, but also pointed out that there are multiple iterations of road names up and down the country which leaves similar room for error in a stressful situation.

For what it’s worth, (as regular hikers and bikers respectively) both she and I both have it on our phones (and the eldest does too) as it makes for a far more accurate system in the grand scheme of things, especially in the more remote areas of Dartmoor where you could be several miles from the nearest nameable hamlet, farm or feature.

Does seem like an issue but seems a bit OTT to throw the whole thing out. If I was lying mangled in a ditch I’d fancy my chances of correctly reeling off 3 words than 6 numbers.

It’s not a safety critical solution but for the general public that can’t read a map, don’t have a map and don’t care having a quick means of identifying where they are it still seems ok.

but also pointed out that there are multiple iterations of road names up and down the country

Compared to a system in which major roads are called a1, a2, a11, a12, a21, b1, b2, b12 etc and there are 1800 Church Lanes, 1287 Church Streets and 1110 Church Roads, it can be forgiven some sins!

Also adding a “fourth” word such as near Luton does help dramatically for clarification.

This feels a bit like an airbags are dangerous so should be banned type argument but I’ll happily be proved wrong

We use it loads for work, to identify site entrances and the lime which aren’t on public roads or row. Nice thing is being able to then navigate to the point using Google maps, which is useful to actually get to site. Makes it simpler than using grid references.

Compared to a system in which major roads are called a1, a2, a11, a12, a21, b1, b2, b12 etc and there are 1800 Church Lanes, 1287 Church Streets and 1110 Church Roads, it can be forgiven some sins!

this. Having plurals as separate “words” does seem nuts though – surely there are enough distinct words available not to have to do that? Or at least something like “measuring”… “measure”/”measures” far too easy to confuse if the line isn’t great or there’s lots of wind noise etc

If you’re sharing the location by sending a link in a message then I don’t think w3w has any advantage over sending the lat/lon.
The only real application where it has an advantage would be reading it over the phone to someone, but in that situation it’s not all that great due to similar sounding words and plurals etc.
The thing is you need to have access to a smartphone or similar to generate the w3w location and if you do then you can probably use something like OS locate which does the job just as well or even better in an emergency situation SARloc which takes the error-prone human reading out words/numbers out of the equation.

This has been all over my twitter feed recently. Not so much the 1 speculation about the Keswick MRT report, but more the maps that clearly show similar words and close but not close enough locations.

Didn;t read the whole blog story, but the one where some guy used some tool to find all homophones and plot all locations with a single homophone location within either 1-2km or 2-5km was pretty concerning. The map of London is practically obliterated by such waypoints. The maps of popular bits of highland Scotland shows a huge number too, with numerous that would give 2 points on different sides of a loch where the mountains on either side are popular with hikers etc.

I spose the thing then is, do any of those duplicates match up with likely paths etc where people might be. The Keswick MRT one certainly appears off-path, but spot on what the GPS probably says.

There’s a reason the NATO/ICAO phonetic alphabet uses unique sounding words. If W3W wanted to be about emergency location then it needs to be unique too, and also international. But sadly they’re not. They’re about proprietary intellectual property rights and protection thereof. Simply posting the 2x 3 words for that story with the cross referenced location in any other popular coordinate system is enough to violate their T+C.

The other story that’s had less prominence is the fact that they are going around filing take-down notices on open-source software projects that replicate what W3W do. And afaict, the UK patent/IP office report declares it non-patentable, and with prior art.

For that reason, I’m out.

I have what 3 words on my phone in case it is useful

For what it’s worth, (as regular hikers and bikers respectively) both she and I both have it on our phones (and the eldest does too) as it makes for a far more accurate system in the grand scheme of things, especially in the more remote areas of Dartmoor where you could be several miles from the nearest nameable hamlet, farm or feature.

If you have a phone and signal there must be loads of ways of sharing your location that don’t need you to read out anything.

I might need it if I find a casualty where there is no signal add need to move to signal

Another white lie is it being a universal system. Every point on earth has an address for every language that they set up the system to work in. So currently ever point on the planet has 20 addresses. If your British in Britain then it’s obvious the address will be in English. It will be much less clear cut you fall of your bike in say Switzerland. Lost at sea will create similar problems

https://play.google.com/store/apps/details?id=uk.co.ordnancesurvey.oslocate.android

https://apps.apple.com/gb/app/os-locate/id810024913

https://northyorkshire.police.uk/contact/emergency-sms-text-service/

If you are going to call the emergency services and use w3w you will need signal and the app.

Or you could just call 999, they send you a text and then your phone sends your location back to them.

As far as I can see W3W seems intent on selling you a system that pushes the idea that the alternative is too difficult for the public. Which it might be, but to use the emergency sms service requires zero expertise and sends a guaranteed helpful location that isn’t licenced.

Advanced Mobile Location
It’s on every Android released in the last decade, and every Apple phone for several years.
AFAIK, it’s already live in UK and loads of other places.
There’s also an EU directive/law for it to be on every new phone.

Just stay on the line when the operator says so, or it does it via SMS, and they remotely locate you, with no need for any app.

Also works beyond the OS grid.

Obviously that doesn’t help those users that just want a nice easy way to tell people an exact place, but this thread is more about emergency location.

Does seem like an issue but seems a bit OTT to throw the whole thing out. If I was lying mangled in a ditch I’d fancy my chances of correctly reeling off 3 words than 6 numbers.

Imagine lying in a ditch with water running over you and a fractured spine and a certified paramedic/mountain guide calling emergency services and them telling him they are not allowed to accept a 10 fig grid reference .. so walk somewhere you can get a signal to download the app!

Then imagine lying in the ditch in winter with hypothermia water flowing over you and a broken spine for 6 hours until the ambulance arrives 15 mins (without sirens and lights) from Gloucester Royal ???

I’ve not really seen the point of it. No better than an 8figure grid reference.
Yes, I know not everyone can read a map and it’s useful to have it on your telephone but you can get a grid ref on there too… Or lat/long which works worldwide, not everywhere is as well mapped as the uk. W3W appears to be another way of doing something which could already be done really easily🤷‍♂️
.
My telephone gives grid refs and lat/long to the nearest 10cm. You can sit perfectly still and watch the numbers at the end change, I assume satellite drift, it moves 20-30cm in each direction

I’ve not really seen the point of it.

Um its a brilliant way to line their pockets… Just offer it for free to organisations that can’t say no* (like Mountain Rescue) and then force them to use it exclusively. Its a brilliant idea for the marketing company.

*I mean Mtn Rescue can say no then they go and tell all their donors they are refusing free software…

Be helpful if it tied into all the DeFib locations in the uk
Could make a difference if you could locate and time a sprint to grab a defib if someone is having a heart attack
I thought the 999 teams did not have w3w enabled yet, pending testing

I thought the 999 teams did not have w3w enabled yet, pending testing

Seems to be dependent on pilots… some are in the pilot. I know someone else on here had a similar experience with the same regional service.

I had a fall on the moors in january resulting in a broken ankle. I could limp on it slowly so the plan was to get to the nearest track where a friend had arranged to pick us up in a farm vehicle and we would get ourselves to A&E. Took quite a while to get to the track whereupon I thought I could feel an Adrenal crisis starting(another story), this requires emergency injection. So OH phoned for an ambulance. When she said we were on a moor they asked for w3w straight away. OH has it on her phone so was able to give our location but it took quite a lot of repeating before the operator could understand her broad wensleydale accent. There was no spelling asked for. On that occasion it did locate us accurately but friend came and got us down to the village before ambulance arrived and we intercepted it in the village.

Imagine lying in a ditch with water running over you and a fractured spine and a certified paramedic/mountain guide calling emergency services and them telling him they are not allowed to accept a 10 fig grid reference .. so walk somewhere you can get a signal to download the app!

Loving the melodrama, but as I understand it, the question is around it being default for ambulance drivers and the potential for errors.

If one were to give any number of location methods to a 999 operator then they would accept them.

I had the impression that W3W was a sort of attempt to reach people that wouldn’t engage in anything that sounded “technical”.

In that vein, I guess it’s less important that it’s perfect for navigation, and more important that it gets people to engage in even the basics of being able to communicate where they are. It’s strength is being “accessible” and I suspect the marketing plays a part in driving that. I also suspect its best use is keeping people away from calling 999 for minor things, rather than being a basis for coordinating major incidents. If you are tossing up whether to use W3W or send a grid ref yourself, you are probs not their target audience.

Imagine lying in a ditch with water running over you and a fractured spine and a certified paramedic/mountain guide calling emergency services and them telling him they are not allowed to accept a 10 fig grid reference .. so walk somewhere you can get a signal to download the app!

Is this a true story? They had signal but not data? The emergency services couldn’t get the handset to report it’s location?

Of course if you are really worried about the above situation then you want a system that will with when your not conscious. Which isn’t that difficult to achieve on any Android phone or Strava. Strava having the edge that if your out of signal for rescuers they will have more data about what you have been doing

After they way they have aggressively targeted whatfreewords who reverse engineered their system to research weakness they can **** off as a company. Marketing ****

Slightly ot but touched on above – the AED situation is a strange one. We have one at work and looked into getting it on a directory in case of nearby emergency – when they last looked into it, there seemed to be multiple competing options and no single definitive national list.

W3W just seems like similar (heavily marketed) duplication.

I had the impression that W3W was a sort of attempt to reach people that wouldn’t engage in anything that sounded “technical”.

it fails though because you still have to download the app and be ready to run with it.
There are alternatives which dodge the “technical” without involving a closed source system. Sarloc or the built in Advanced Mobile Location which is available on most modern phones. They dont have the same marketing budget which in itself says something about W3W.

Quite unusually, I have a relatively well informed opinion on this! So stand-by, long reply incoming.

I’ve been with Mountain Rescue for a good few years now and, as an Incident Controller, I’m one of the guys who takes the callout from the police and tries to make sense of things to send the troops to right place. In that respect, I’ve been given locations as OS grid references, screen shots of apple/google maps, lat/long coordinates (nightmare), road names, physical descriptions (you know, near the big tree) and pretty much everything else you can imagine.

W3W is common now as as a tool and for pinpointing a GPS location its good. I treat it not like actual words but instead as a reference. Every letter is read out, I repeat back to caller then its checked in real time if situation allows. I then have a look to see if it makes sense and when I add it to our Incident Management system (SARCALL) it automatically converts it to OS and drops a pin on a map. But, I never trust any location provided by a casualty or police. So every time, without fail, I will send a PhoneFind command to the callers phone. This arrives as a text, they give permission and it pings me back a location (as OS GR). Even this isn’t fool proof though. The caller may not be in the same place as a casualty, they may not give permission, battery may of failed, they may be in a panic etc. So what is critical is taking what info you have and building a picture.

W3W gives an accurate location, all of the apps do, it is peoples translation of the words (caller or call handler) which is not accurate, that is why it needs to be read letter by letter and confirmed, plotted and checked whilst people are on the phone. This is no different from reading out a GR, and I’ve been given plenty of duff GR’s before.

We are seeing police and ambulance using it more and more now. Ambulance in particular if they arrive on scene first, it means the paramedic can send a location easily whilst focussing on important stuff like saving the persons life.

Yes, OS locate is just as good / better but they don’t have the marketing budget so people don’t put it on their phone. W3W do have that reach and, as a result, it is very common now and more people are in a position to use it when in bother. As we can convert it usefully it is fine as a tool. Critically, it is much more accurate than most people attempting to plot an accurate location on paper map under stress. I’m totally cool with it. If there are any failings it is not with the tool but users application of it.

Avoidance of issue is easy, send the location from W3W as a message if possible, then nothing is lost in translation.

Some mention above about default location finding built in to Android / Apple and accessible by police. As far as I know police can’t access this without some pretty heavyweight permissions from above which take time. That is why they also use the PhoneFind tool quite a bit as it prompts user to give permission before location is sent. We can triangulate signal if needed but it is of limited use, we generally only use this when looking for people who don’t want to be found (surprisingly often).

If W3W use their marketing budget to get ‘location finding’ as a tool out to the masses then it is fine with me.

As an aside, there are some interesting trials of technology which picks up a phone which has no signal but is sending out data as it tries to find a signal. If we can get that small enough to stick on a drone it will be amazing in poor signal areas.

In summary, if you are calling Mountain Rescue I don’t care if you use OS locate, W3W, Strava, or good old map and compass. Give me a location, I’ll add it to the story and check everything using whatever tools we have

I don’t agree with the OP title, “What3words not suitable for safety critical applications”. Of course it is suitable, just plan for confusion and double check everything.

Final words though, if you want a quick response please do follow the rules and call 999, ask for Police and then Mountain Rescue. For reasons which are too boring to go in to, this will often mean you get a quicker response than if you ask for Ambulance first. The outcome will be the same, you will get all of the resource you need, but less likely to be delayed in control room process if you ask for police first.

Mleh, I have it on my phone, along with (by memory) two other ways by which I could give a pretty precise location information to any-one who may need it Bear in mind the very first thing most ambulance services will ask for is a postcode. The knowledge that in order to get mountain rescue you have ask for the Police when calling 999 (which makes no sense) and will probably be a biggest stumbling block for the sorts of folk for whom grids or lat/long are too difficult anyway

I get that lots of folk dislike the propriety nature of it, and the nonsense doom mongering of “They’ll be forced to use it” is just so much more of the “Sky is falling in” stuff that’s trotted out endlessly either about access or ROW or whatever that has always stalked outdoor pursuits for as long as I can remember, but never seems to actually ever happen. It’s just another business staking out a patch of ground. Either use it or don’t. Who cares.

Edit: the only use for it so far that I’ve found remotely useful is when 2 people have it and if you’re in an unfamiliar town/city and you can’t find a street name Send this and you phone can walk you to where the other person is. My daughter and I used it this way a year back or so, and it was cool/fun.

They dont have the same marketing budget which in itself says something about W3W.

The advertising and building familiarity / accessibility to a broad range of non-outdoorsy people are all “the point”, surely? Most people don’t buy iPhones because they’ve carefully weighed the technical specs with all alternatives. Make it accessible and non-geeky and people will use it. This audience of people isn’t going to download some niche app for mountain walkers.

The only question here is “is it worse than nothing” in navigation terms.

Some mention above about default location finding built in to Android / Apple and accessible by police. As far as I know police can’t access this without some pretty heavyweight permissions from above which take time.

As far as I am Advanced Mobile Location doesnt need those heavyweight permissions. Its tied to the 999 (or equiv) number and so can only be used when someone phones that number.
No apps or anything else needed for newer phones and certainly not a location system from a company which is desperately trying to capture the market before it can then engage in the traditional make lots of money.

If there are any failings it is not with the tool but users application of it.

I disagree. The tool doesn’t give the lack of ambiguity in location that its sellers claim. It’s been demonstrated that there are many confusable pairs within a confusable distance of each other. The algorithm used to allocate words is supposed to avoid this, but it’s flawed. So whilst there may be failings in the use of the tool, there are also failings in the tool itself.

I don’t agree with the OP title, “What3words not suitable for safety critical applications”. Of course it is suitable, just plan for confusion and double check everything.

Well, that’s title of the blog by the guy who identified the flaw in the algorithm, and I think it’s a fair statement. W3W claim that any confusion will lead to a location that is so far out that it’s effectively self-checking, and that’s clearly not the case.

It’s good that you’re so careful in using a flawed tool but it’s clear that others are not, as per Jordan’s post.

I disagree. The tool doesn’t give the lack of ambiguity in location that its sellers claim. It’s been demonstrated that there are many confusable pairs within a confusable distance of each other. The algorithm used to allocate words is supposed to avoid this, but it’s flawed. So whilst there may be failings in the use of the tool, there are also failings in the tool itself.

But you don’t know that confusable pairs was the cause of the Keswick error.
I do agree though, if W3W say they don’t have confusable pairs, they shouldn’t have them.

there are also failings in the tool itself.

don’t use it then.

There’s a workaround for W3W. It’s very unlikely you will find 2 sets of confusable pairs adjacent to each other, so if you give the W3W combo in 2 spots next to each other (i.e that are 3m apart), you should be pretty confident in the location. Not going to work if you’re unable to move, but oftentimes that’s not the case.

Mleh, I have it on my phone, along with (by memory) two other ways by which I could give a pretty precise location information to any-one who may need it Bear in mind the very first thing most ambulance services will ask for is a postcode. The knowledge that in order to get mountain rescue you have ask for the Police when calling 999 (which makes no sense) and will probably be a biggest stumbling block for the sorts of folk for whom grids or lat/long are too difficult anyway

The recent incident I was was involved with I believe the caller asked for ambulance, we/I gave the call handler Grid and what three words (they requested WTW) and they got the air ambulance on the way. They alerted Mountain Rescue rocked up later and coastguard winched the casualty.

It will be on the telly sometime next year

ampthill

Is this a true story? They had signal but not data? The emergency services couldn’t get the handset to report it’s location?

Yes (except the stream was shallow and didn’t go over his body)…

The casualty wasn’t in our party but we found him as we followed him and his party down.

I was with an ex army paramedic who phoned his (now) wife who was an A&E doctor (ironically until she broke her spine then retrained to be a GP) one of the other guys was ex-RAF paramedic but the guy Tom (L3 coach and mountain guide) the one who got told to download w3w) was the most qualified and was also convinced of a spinal injury. (Tom knows the locations by heart for where a helicopter can land and where ambulances can get)

The poor bloke was literally lying in a stream for 6 hours… and they were either unable or unwilling to use any other form of location. I suspect unable as they were I assume in a pilot

Steve, just out of curiosity, do you know if they phoned police or ambulance? It shouldn’t matter but, unfortunately it does sometimes make a difference.

The situation you describe is not the fault of W3W, it is entirely the fault of the control room training or process.

The poor bloke was literally lying in a stream for 6 hours… and they were either unable or unwilling to use any other form of location. I suspect unable as they were I assume in a pilot

That’s a terrible story. Whatever the systems are the fact that they wouldn’t even start a process to recover him from partial information must be a failure of process

Thanks @franksinatra for the practical, pragmatic and experienced view.