Our story earlier this week about a new smartphone app that uses AI to analyse video and enables users to report drivers suspected of speeding to the police for potential enforcement attracted a lot of comments, including from Rod King of the road safety campaign 20’s Plenty For Us, whose volunteers are trialling the app.
> New smartphone app to allow public to submit evidence of speeding drivers
Among the concerns raised about the Speedcam Anywhere app were whether police would have the desire, let alone the resources, to deal with such submissions, as well as whether there are evidential issues related to the footage captured.
However, replying to road.cc readers in the comments to the original article, King said he believes the technology “will be transformational” and that he has “every confidence that it will make a huge difference” to road safety.
He said: “I think that it’s fair to say that the forces aren't expecting this. So don't expect systems to automatically accommodate the new technology.
“I am confident that it will be accepted, but we do have a very patchy set of constabularies on enforcement, especially ‘where people are’. There will be pioneer forces who will see the benefits and others who are still only migrating from Gatso [speed cameras].
“The point about uploading video and report is that the report saves analysing the video. But if challenged the video can be manually analysed also. It’s all a lot more straightforward than analysing most dashcam or headcam submissions.
“It will be transformational. But some forces may take longer to transform than others. I have every confidence that it will make a huge difference.”
We’ll be contacting the app’s developers for a response to a number of concerns raised by road.cc readers, as well as getting some thoughts on it from road safety professionals.
In the meantime, 20’s Plenty For Us director King gives more detail about the app and how it functions, which will hopefully answer a number of the questions raised in the comments. He has also highlighted that more information is available on the organisation’s website.
King said:
Most speed detection ‘devices’ use a function within the device to measure the speed of a vehicle. If it’s rad or laser, it involves measuring the speed by bouncing a wave off the oncoming vehicle and measuring the doppler effect produced because the vehicle is moving.
One issue with this is that you can rarely use the device in the path of the vehicle and therefore you do not measure the vehicle speed as it is reduced by the cosine from the sight line to the direction of travel. Because the device independently assesses the speed it needs calibration.
Speedcam Anywhere is different. It is not the smartphone that measures the speed. The app buffers a video image and when you press the shutter as a car is passing and centred on the screen it selects a video snip of the previous one second and next one second. This is then uploaded to the cloud together with GPS location. The server then:
- Uses ANPR to look up the vehicle make, model and year;
- Looks up the wheelbase (WB) of the vehicle;
- Uses AI to analyse the video and locate the wheel centres;
- Finds the still in the video clip where the front wheel passes a point on the road. Takes its time stamp (T1);
- Finds the still in the video clip where the rear wheel passes the same point on the road. Takes its time stamp (T2);
- Uses the simple physics calculation that v=s/t ie v= WB/(T2-T1);
- Looks up the mapping to find the speed limit at that point;
- Creates a two second video clip overlaid with the time stamps;
- Creates an A4 report showing location, picture of vehicle, its details, location, speed and speed limit as well as time stamped stills used;
- Sends a summary back to the app.
The app user is then able to download the report and video clip for upload to the police dashcam. Here police can (if they wish) examine the video to verify the speed of the vehicle.
Because the wheels always follow the direction of the vehicle the angle of approach does not matter. You can use the app with oncoming or departing cars as long as you can see the number plate. A line of sight with one edge of the image perpendicular to the road has been found to work best.
The requirement for a Home Office Type Approved device only exists for speeding convictions. It is an anomaly that presumes that the speed is measured on the device. Where it is a video, precedents have already been set whereby drivers have been prosecuted for careless or dangerous driving based on video evidence. This includes verifying speeding.
However, this does require expert analysis and often a measurement of road markings or scenery to provide a fixed distance to measure the travel time over. Speedcam Anywhere negates the need for this expert analysis by using AI and the wheelbase of the car as a fixed distance.
Section 59 Anti-Social Driving offence only requires reasonable grounds for believing that a motor vehicle is being used on any occasion in a manner which contravenes section 3 or section 34 of the Road Traffic Act 1988 (careless and inconsiderate driving and prohibition of off-road driving) and is causing, or is likely to cause alarm, distress or annoyance to members of the public. Hence under "reasonable grounds" a Section 59 offence can be registered.
Speedcam Anywhere could gain Type Approval for the ‘process’ rather than the ‘device’. In which case police and members of the public may use it for enforcement of speeding offence directly.
This really does use a great combination of modern databases, smart analysis and AI to provide an accurate measurement of speed using a smartphone. It’s not only a great invention but also a huge step forward for enforcement. When driving in the future then, any pedestrian you see could be a Speedcam Anywhere pedestrian. Especially in urban and village settings drivers should be wary of blasting through those public places between buildings that we call streets. After all, 20 is Plenty where people are.
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FWIW, from the Gruaniad today:
The app cannot lead to drivers receiving speeding tickets. Since Speedcam Anywhere’s algorithm has not been vetted by the Home Office, it is not legally a speed camera, and cannot provide sufficient evidence for a police force to issue a prosecution for speeding, although the broader “dangerous driving” offence may apply if the driving is sufficiently negligent.
https://www.theguardian.com/world/2022/apr/10/speed-camera-app-developer...
Same article also says the developers had to become anonymous due to the amount of vitriol received from irate car drivers comparing them to the Stasi...
There's a surprise then.
There's a Feedback button on their website. I just sent them this:
This app must have Cycling Mikey all moist in anticipation of spending his waking hours pointing his phone at passing motor vehicles..
And? I don't race but I'm
delighted atindifferent to the thought of people being unable to sleep for excitement because Shimano are bringing out an even lighter Ultegra groupset (did I get that right)?I'm sure you have said you used to be a Policeman in Australia. So you are so jaded that you would just let people break the law? You do realise that Mikey lost his dad due to the actions of an illegal driver. Sounds like Autralians should be glad you are no longer in charge of Policing laws.
As a physicist what this app proposes sounds like it will work very well and accurately to within the specified accuracy.
To those people mentioning AI: AI is only used to identify the vehicle make and the video frames where the car passes a certain point. Both of these outputs can be easily verified by human inspection.
To those people mentioning clock drifts: Quartz oscillators used in phones are accurate to within about 1 second per day, that's accurate to within 1 part per 100'000. That's more than enough for generating an estimated speed of travel.
To those people mentioning that the person filming could be moving: Yes, however this would inevitably result in a shaky video and blurry images unless you're using a steady-cam, and you would have to be moving at a fast jog to make a car appear to be traveling significantly beyond the speed limit when it isn't actually. Additionally, the photo view points won't line up and this will be obvious.
The biggest technical hurdle is likely the image quality and frame rate of videos, but with cameras advancing as they are this is likely easily to be overcome.
The biggest operational hurdle is the time it takes to get out your phone, start the app, and hit record. By that time the car is long gone.
I would love to see this technology used by the police for speeding cameras. Set up Go-Pro sized cameras on traffic lights and Bob's your uncle.
I changed the settings on my phone and 8 hours later the difference to the 'real time' is not discernable - can only be a few milliseconds.
Your phone is connected to a cellular and GPS network though. It'll be doing a periodic sync, same way when the clocks changed it updated.
Its good to see this discussion.
The analysis report from the video clip is shown below. This explains the physics of the measurement of the speed. The wheelbase is not subject to variation by more than a couple of millimetres. The frames where the wheels pass the fixed point are shown together with their time stamp. For there to be a 5% error in the clock, and hence the time interval, the phone would be losing or gaining over an hour a day.
The clip and frames are able to be examined retrospectively in order to verify the measurement. The direction of travel of the vehicle compared to the user is not relevent because the measurement is in the same line as the direction of travel of the vehicle.
I trust this helps. Rod
Is it possible that phones' internal clocks really are this bad, but because they regularly resync with the network clock we never see the gross effect?
Change your settings and let us know !
nope - 1/100000 accuracy for the oscillators
I'd rather be safely passed at 36.1 than run over at 30. Improving skills and attitudes leads to less people being run over. Improving skills and attitudes also leads to drivers being competent enough to set a safe speed, which is often below the legal limit and sometimes above. Please look up the road ahead and make sound judgements based on anticipation and hazard perception. Speed limit enforcement is one small part of road safety. Coaching road users that it's all you need to worry about is not very helpful.
I'm not sure that first part really makes much sense even though several people like that phrase. "I'd rather have an unpleasant / frightening experience than be injured or killed" - doesn't mean much does it?
I'm all for better training and attitude but that alone won't make us safe of course - so enforcement is still a part of it. However:
Nope.
So if you stand on the kerb holding your smartphone filming passing cars i'd imagine that you'd very quickly no longer be the owner of a smartphone in most parts of London.
How is that any different from making a call or checking a web page ?
No different; I'd suggest his point is people have had their phone snatched out of their hand; I've seen video's of just that happening in London.
I can't believe you live in London if you've posted that.
Thinking more about this , it could just be the start . Every app. created seems to spawn a rival with new enhanced capabilities that ever more powerful phones can use . Will we maybe see cycle camera systems that do the same as this app too, if linked to your phone ? Dunno whether to be pleased or worry about increased surveillance.
And how exactly is accuracy ensured?
Police equipment for measuring speed and cameras rightly have to be calibrated and checked and recalibrated periodically, annually I think?
All I'm seeing is buzzwords like AI. Can you even be sure of accuracy of the recording? How does this account for a cheap phones that may likely drop frames on a recording.
Sounds like BS to me. Either an April fool or scam to get money out of investors.
Easy to count the frames and reject if the frame count does not match the standard FPS.
Two decades in broadcast I can tell you it really isn't easy. What's the apps time reference for calculating speed. The internal clocks of consumer grade devices are notoriously bad, and we are talking consumer grade GPS. Then there's the use of the vehicle wheelbase, this isn't very large even for for something like a range rover, so what's the margin of error? With such short variables I fail to see that the angle doesn't matter. Then there's the matter that you need a clear shot of who was in control of the vehicle. And again how can any of this be valid when police equipment must be calibrated to pass as evidence.
"The internal clocks of consumer grade devices are notoriously bad, and we are talking consumer grade GPS."
GPS is used for location so will be ok and when you say 'notoriously bad' what do you have to support that claim?
Fixed penalty traffic cameras don't have a clear shot of who was driving, the letter is sent to the keeper.
GPS is also used for accurate time synchronization. Every piece of IT and broadcast hardware I work with is sync'd to four NTP servers or for more critical kit PTP (precision time protocol) servers all of which sync to redundant GPS receivers. If anything loses sync you will quickly see drifting time, if it's broadcast kit you're liable to impact transmission with glitches and flash frames if something in the chain is out of sync with everything else. This is all kit that is a factor or tens or hundreds times more expensive than a mobile phone.
You're describing a problem of synchronisation between different pieces of kit, which all need to keep step with each other and also with an independent reference to within fractions of a frame. I can see that is difficult.
However, if a mobile phone clock has drifted out by frame or two over a 24 hour period that makes little enough difference to the speed calculation. Moreover, a tolerance can be allowed for, so motorists filmed apparently doing 60mph in the High Street are not going to get off because a smart lawyer proves they might only have been doing 53mph.
In any case, if the app is using a GPS time signal then really we are not talking about the phone's own clock accuracy. Unless you are saying there is a variable time delay in GPS signal processing pipeline.
No, I'm saying time accuracy is important in determining speed. All I have done there is explain for hirsute how GPS is key to ensuring time doesn't drift, as well as giving an example of how time is not accurate in even expensive devices reliant on time unless they are externally sync'd. You also cannot rely upon getting a GPS lock on a handheld device, particularly in a built up area like a city.
Honestly this whole thing seems pointless to me. Given most incidents are fleeting, you may as well just use your phone's camera to record.
All of your mostly valid points relate to speeding convictions, as the article states this apps use is targeting the section 59 offence of careless driving, thats the same bit of legislation that allows dash cam submissions for close pass prosecutions & doesn't require Home Office type approval, calibration or any degree of specific accuracy, beyond reasonable doubt the offence was committed.
You could just as easily now, and I have done this although the result was NFA, take dash cam footage, apply a bit of Galilean physics and output the same speeding data for a careless driving submission, all the app does is send it to a computer (AI) to do that calculation bit for you. Its then down to the police force to decide what to do with it.
And the app is called speedcam aware, and being touted as able to calculate speed accurately. So my "claims" are pretty relevant.
"You could just as easily now, and I have done this although the result was NFA, take dash cam footage, apply a bit of Galilean physics and output the same speeding data for a careless driving submission, all the app does is send it to a computer (AI) to do that calculation bit for you. Its then down to the police force to decide what to do with it."
And again, what is your margin of error? This is little more than throwing grass in the air to see how the wind is blowing, when applying to a vehicle breaking a speed limit unless by a huge margin.
It's a valid point to query accuracy of the output data, but dont get hung up over it imo, because sec 59 prosecutions don't require absolute accuracy, the reviewing officer just has to be satisfied an offence has happened.
For my own example the calcs I did, I think I measured over 20metres via obvious landmarks, not too dissimilar to how i calculate time gaps in road races using broadcast pictures when the OSG fails. Backed it off against my own speed sensor & distance data to validate and was comfortably at worse just 90% accurate. Which given the speed I calculated was near double the posted limit on the road I thought was satisfactory. There was no way the vehicle I reported was travelling at or close to the speed limit.
But the police NFA'd the submission because they cited the we cant prosecute speeding without a certified calibrated camera, which is absolutely correct,but they completely missed that sec 59 was an option.
And its that rather than any debate on accuracy,or type approvals, or even name of the app that's the main issue, will the police pursue sec 59s.
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