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This blog post was published under the 2015-2024 Conservative Administration

What we’re working on: PN testing and cameras in garages trial

Posted by: , Posted on: - Categories: MOT Modernisation, MOT testing service, News and updates

In this blog post, I wanted to update you on how we’re going to improve emissions testing on diesels (known as PN testing) alongside updates on how we’re better using and sharing our data. We’ll also explain why we’ve paused the roll out of cameras in garages. 

Piloting Particulate Number testing 

smokey diesel car exhaust

We are working on improving how we do emissions testing on diesels (known as Particulate Number (PN) Testing) will proceed with more pilot work.

Why we’re looking into this 

Research conducted by the DfT into the use of PN testing equipment for the MOT concluded that it provided an effective means of identifying removed or damaged DPFs (diesel particulate filters), with significant advantages over current testing methods. We know some countries across Europe already use PN testing during their MOT test, and we’re looking into whether it would be feasible to do that in GB. 

Whilst the current diesel emissions test measures the density of the smoke emitted from the vehicle, it doesn’t measure the size or quantity of the particles within that smoke. We now know that these smaller particles are very harmful to us and therefore measuring them will bring both air quality and health benefits.  

How the trial will work 

We’re working with 10 garages of varying sizes over the next few months to trial a few different models of PN testing equipment. Once we have enough data, we’ll be able to decide whether it is practical to bring this into the MOT, and which PN tester types may be most suitable.  

We know garages may have to invest in this equipment, so we want to reassure you that we won’t be making these changes without thorough consideration – and we do understand that uncertainty about dates of first MOT (for example) can affect those investment decisions a garage may make. But it’s important we do what we can to keep everyone safe by improving air quality – and that maximising the value we get from the MOT helps secure its future. 

Modernising the MOT 

We understand that no matter what happens with the potential MOT modernisation, it will need careful and considerate change management. This will ensure that industry and other stakeholders are properly engaged and involved in future decisions.  

DfT are therefore establishing a stakeholder review group that industry trade groups will be involved in to help guide this work if needed. We hope this will be a good way for the ‘voice’ to heard in future changes. 


Cameras in garages trial 

Confirm vehicle details for test

In my last blog post, I mentioned that we’ve been investigating and trialling the use of connected cameras in garages. This will enable testers to use a device with a camera built in, like a phone or a tablet, to take a photo of the vehicle’s number plate that you’re testing and upload it to MTS. 

We had planned to begin the second trial with this new software in May. However, this will now be a bit later as we need to do some enabling security work first. It’s important we make sure MTS is protected against viruses or other bugs that could occur when people are uploading photos – hence this taking a little bit longer. We’ll let you know how this work progresses and when we’ll be rolling out the second phase. 

Our latest blog post written by Neil Barlow, DVSA’s Head of Vehicle Policy and Engineering is about our recently published strategy and vision and how we will be working with you to implement it. You can read it on Matters of Testing How our strategy and vision will affect the future of the MOT - Matters of Testing (

Making it easier for customers to know if they have a safety recall on their vehicle  

MOT tester in front of computer screen

A big piece of work we’ve been developing over the past few months is improving our safety recalls data, and how we communicate this to motorists. 

Whilst we currently provide vehicle recalls information on our check MOT history service, this data isn’t real-time. We’ve been working alongside major manufacturers to get real-time updates from them. Using their data, we’ll make improvements to our digital services to make it easier for motorists to see if their vehicle is subject to a safety recall.  

We’ll make some further announcements soon. Once this feature is in, we expect more manufacturers will share their data in this way. This will make this increasingly useful until, eventually, we have all manufacturers on-board. 

As always, please let us know your thoughts in the comments section and we’ll do our best to come back to any questions you have.  





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  1. Comment by Adam posted on

    Will the use of cameras to identify the vehicle be for car M.O.T only or hgv too?
    Think this will be a great help and make the trusty clipboard a thing of the past.

    • Replies to Adam>

      Comment by Neil Barlow posted on

      This is initially for light vehicle - cars etc - in the MOT scheme. You make a good point, that if this approach works something similar could work for HGV (or PSV for that matter).

  2. Comment by Richard posted on

    Anyone seeing a lot of vehicles coming through with expired mot's? I'm not talking days or weeks, some have not had a valid mot test for months. Bearing in mind, there are various options for a reminder.
    When I've enquired why they've left it for so long, thier reply "the chances of getting caught these days is pretty low"

  3. Comment by Simon R posted on

    As the AEDM of a test station that has recently had to purchase a new 'connected' emissions machine for nearly £4500, I'm slightly concerned about the thought of having to purchase more, probably very expensive equipment? Especially considering the price of an MOT test hasn't increased in over 13 years! Will later existing connected emissions machines be able to be converted for this new type of testing or will our newly purchased machine become completely redundant?

    • Replies to Simon R>

      Comment by Simon Smith posted on

      Hi Simon, existing emission equipment is unlikely to become redundant as PN testing will only apply to vehicles which are required to be fitted with a DPF

      • Replies to Simon Smith>

        Comment by Simon R posted on

        Good point Simon, hadn't thought of that. On that note then, surely will we need DVSA to issue all testing stations a complete list of all cars that were fitted with DPF as standard so we don't carry out the wrong type of emissions test?

        • Replies to Simon R>

          Comment by Neil Barlow posted on

          Early dates yet, but likley would be something simple like "All diesels with date of Manuf' after XXXX". Or something like that.

          • Replies to Neil Barlow>

            Comment by Simon R posted on

            I wasn’t aware there was a set date for DPFs becoming mandatory? If there is why haven’t testers already be given this information? It would make life much easier when deciding if a vehicle has had it removed or it just wasn’t fitted from standard

  4. Comment by Stephen Blackwell posted on

    Recall data, This should be printed on the MOT paperwork so the customer knows that it is needed and if they don't carry it out by the next mot (2nd time of warning them) should we fail the MOT ?

    • Replies to Stephen Blackwell>

      Comment by Simon Smith posted on

      Hi Stephen, the recall will be printed on both pass and fail documents currently issued, future failure at MOT is a consideration we're exploring for the future

  5. Comment by William Atkinson posted on

    The way things are going in this industry garages won't be able to afford all this equipment you are talking about it's hard enough to make a living at the moment without burdening MOT stations with more financial outlay and the costs of calibration is through the roof people are treading water it's fine for the boffins at your end to come up with these ideas but it's the garages that have to bear the financial cost the way things are going there'll be a lot of stations calling it a day maybe that's what you want

  6. Comment by Iain Gorrie posted on

    Can you explain the benefit of camera use as opposed to using the keyboard as currently used please?

    • Replies to Iain Gorrie>

      Comment by Olivia (DVSA) posted on

      Hi Iain, this will help reduce record keeping errors as you won’t need to enter the registration plate manually. This should also help save time during the test.

      • Replies to Olivia (DVSA)>

        Comment by Neil Barlow posted on

        And of course avoiding those errors - from memory we see several 10s of thousands a year - avoids a whole load of hassle for motorists when they come to tax their car and DVSA / the garage in putting things right!

  7. Comment by lee, Cheshire posted on

    i think the introduction of camera would be a great step to the security of the system and make it hard for the few rotten apples to abuse the system. on the green issue i think PN testing is the way forward to police diesel engine emissions.
    I can't finish without bringing up the price issue, the DOT has not moved on the maximum pricing for 13 years, with everything that's going on at the moment and the possible extra investments garages will have to make this should be addressed, i understand garages are still discounting and even offering free mots but we all know even charging £50 we don't make a lot.

  8. Comment by Sanj posted on

    All this is lovely but you need to up the charge for the mot and stop discount tests and no pass no fee stations,fixed fee all across the board. Too many people being ripped off and too many illegals being done.

  9. Comment by Philip Gilbert posted on

    I think the price of mot's should be increased significantly before there is any thoughts of adding changes to testing, DVSA' big ideas usually cost the garage owners.

  10. Comment by Mark Benton posted on

    As a full time tester I love to be challenged by any decision I make
    My tests are done by the book
    So any technology to improve a better resolution to explain to the presenter why the particular filter as failed.
    Should they say its been cut open to be cleaned out etc
    This would make it easier to prove the pn is incorrect .
    Hopefully the trial has been put into stations testing slightly older vehicles
    Unlike me at a main dealership testing newer cars that are highly unlikely to have been tamperd with
    However this will not combat fraudulent tests as the smoke machine can be put any exhaust system
    My only concern with even more technically is that it would make the mot longer to carry out as some testers are expected to get the job done quickly not that my employer gets away with this
    I'm the tester not them so I do it at my pace

    • Replies to Mark Benton>

      Comment by Neil Barlow posted on

      Thanks Mark. Agree - as for any part of the test, the PN testing will be heavily reliant on the tester using it right on the right vehicle. There may be other things we do in parallel about better tackling fraud - but this particular thing is not really about test fraud. On time for test, as I understand, early trials show no longer than the current opacity test.

  11. Comment by Paul Hamilton posted on

    If workshops carrying out MOT Tests are going to be required to buy some new equipment, what are the chances of an increase in the cost of a test fee?

  12. Comment by Clifford West posted on

    This PN system should also be used on petrol vehicles as well.

    • Replies to Clifford West>

      Comment by Simon Smith posted on

      Hi Clifford, research shows particulates emitted by diesels compared to petrol are far more harmful to humans with different chemicals. Testing these may be a test of the future

  13. Comment by ABDUL RAUF posted on

    This is very good for mot testing

  14. Comment by David posted on

    All this new implementation is a step forward in testing but the most important issue for all testing stations at this moment in time is cost surely the testing fee should be the first priority change otherwise there will be a shortage of testing stations and testers as businesses look to more financially beneficial ways of income

    • Replies to David>

      Comment by Neil Barlow posted on

      I do agree, that were there is substantial investment required - then the depreciation effect on the fees will need to be looked at. Looking at that will have to go hand-in-hand with any decision on new equipment.

      As an interesting side note - MOT garage numbers are still rising. So at present, we aren't seeing a shortage - even with all the challenges that others have mentioned.

  15. Comment by Sue posted on

    Interesting that more work and more investment is required by garages providing mot’s. Yet still no increase in the fee garages can charge. Based on the time taken to do a mot, the rising cost of wages, calibration and other expenses to run a garage. The cost and time for annual Mot training. All costs being born by garages. Discounting competition from the likes of Halfords. There will be a time when small independent garages will stop doing mots.

  16. Comment by Chrismotman posted on

    More expense on emmisons machines that we have just had to replace at a huge cost and an update just forced on us. Although I agree with taking a photo of the car that’s on test. I think emmisons machines should be abolished for obd scanning for readiness test passed on newer cars like other countries.

    • Replies to Chrismotman>

      Comment by Simon Smith posted on

      Hi Chris, Though OBD can detect some issues within emission equipment, removal of the internals of a DPF and re-mapping cannot be detected if this has occurred.

  17. Comment by Martin posted on

    I would hope your trial on PN testing is taking place in varying demographic locations and not just your favoured few like you seem to have done in the past .
    Before you get too carried away with all the expensive high tech equipment which will put yet more financial pressure on VTS and result in many abandoning the MOT scheme you need to correct all the mistakes , omissions, spelling and grammatical errors in the current MOT system and make it fit for purpose.

    • Replies to Martin>

      Comment by Simon Smith posted on

      Hi Martin, the PN trial is being conducted across a variety of test stations nationwide, both in cities and rural areas so we can achieve a balanced view.

  18. Comment by Peter Miles posted on

    So, do you envisage testing stations to have to replace diesel emissions testing equipment again? And is the maximum permitted test fee to be increased to cover this cost?
    If not how do many test stations do you expect to remain open?

  19. Comment by Chris Nicholson posted on

    When is the DVSA going to make it compulsory in mot stations to have exhaust gas extraction systems fitted as part of the mot kit , you have stated that exhaust gasses and the particles within the gas are very harmful to us so why are you not protecting your mot testers and the staff working within these garages, I have been in the trade for 40 years and I was an mot tester for 35 years, I wonder if I will even get an answer from DVSA ?is the DVSA responsible any health problems that may occur due to working within these testing stations, is the DVSA liable, negligence , I wait for any response, but I won't hold my breath, too many particles in my lungs, Many thanks Chris Nicholson.

    • Replies to Chris Nicholson>

      Comment by Neil Barlow posted on

      I don't think it is for DVSA to specify the other safety equipment that garages need to be a safe place to work. So each garage - be it for MOT or its other work - should be considering those risks. The answer may not be forced extraction, but the risk should have been assessed and, where necessary, mitigated.

  20. Comment by steve posted on

    Anyone know how much extra Co2 is produced (which is the gas that is apparently going to kill us all) regenerating all the DPF's fitted to vehicles?

    • Replies to steve>

      Comment by Simon Smith posted on

      Hi Steve, during DPF regeneration the burning of accumulated soot does produce carbon dioxide which naturally occurs in our atmosphere and is not as deadly as carbon monoxide. Regeneration of DPF's is heathier than no regeneration taking place.

  21. Comment by RG Tucker posted on

    The cameras will get rid of some of the cowboys or make them strait.

    • Replies to RG Tucker>

      Comment by Mark Marsden posted on

      No it won't anybody can take a photo of a reg plate doesn't mean it will get an mot

      • Replies to Mark Marsden>

        Comment by Neil Barlow posted on

        That is true. But it makes it harder again. And when we review a photo and it is clearly sitting in a car park - that will be helpful evidence. Stopping fraud isn't about just one step - it is about multiple interventions; but those need to be proportionate.

        • Replies to Neil Barlow>

          Comment by Mark Marsden posted on

          Why would it be sitting in car park it could be at the garage on the ramp but nobody testing it using emission readings from another vehicle and just making brake readings up you will never stop fraud in the MOT system while the car trade is run by crooks I'm afraid

  22. Comment by James moar posted on

    Seems like good positive progress all your hard work will pay off Retired tester

  23. Comment by Mark Marsden posted on

    Glad I'm nearly 61 and not got long from retirement the MOT test is now becoming a play thing for people in offices who have nothing better to do ,I personally always thought the MOT test was about road safety obviously is not anymore its a tick box situation ,from a nearly 39 year tester who his totally disillusioned with it all

    • Replies to Mark Marsden>

      Comment by Simon Smith posted on

      Hi Mark, whilst the majority of the MOT relates to safe vehicles from a mechanical perspective, the health benefits to us all with cleaner vehicles can only be a good thing.

  24. Comment by andrew guye-johnson posted on

    when is the price going to increase and not a few pence ! MP have had a good increase we have not for years and you are worried about quality of test ! its a joke mot test stations dont find funny !
    when was the price last increased ! ......years ago !

    • Replies to andrew guye-johnson>

      Comment by Richard posted on

      I reckon they will put the price up. BUT, with the talk of extending the annual mot for some vehicles to every 2 years, it'll still hit garages in the pocket.

  25. Comment by Siyavash_sadough posted on

    Great idea when implemented

  26. Comment by John bentley posted on

    Which vehicles do you think are able to pass the current test which shouldn't?

  27. Comment by peter owen posted on

    i will stop doing mots when my personal liberty is infringed and if i have to pay for all this unwanted equipment .
    I have to also consider my rent contract length and whether it is worth it.

  28. Comment by E fisher posted on

    The current system sends three recall à if safety is implied.then you will be told by the manufacturer if you do not reply to the recall it will be past on to dvla. So why do we have to enforce it.when we have to let vehicles with dangerous defects drive away

    • Replies to E fisher>

      Comment by Neil Barlow posted on

      At this stage this isn't about enforcing - this is about providing the information in different ways to the motorist (they may not have seen the letter for whatever reason).

      However, there is a thought that we could and should fail at MOT for a outstanding defect where a motorist has had every opportunity to get it sorted but chosen not to. But - that isn't likely to happen very soon - and there are quite a few steps before we get there.