RSS Expert Helps Quash
Dangerous Driving Appeal


A man has been banned from driving for 12 months and fined £1500 after being found guilty of dangerous driving on the A4121 Trawsfynydd to Bala road, North Wales on Sunday, October 15 2017.


After being convicted of the offence by Magistrates at Mold, North Wales, in July 2018 Michael Roberts mounted a vigorous appeal against that conviction being convinced himself his driving was not dangerous. 


His appeal against the conviction at Mold Crown Court was rejected on Friday 15 February 2019. 

The magistrates had convicted Roberts after viewing dashcam evidence submitted by the driver of a Honda CRV who had come to the opinion that the manoeuvre was dangerous.  The dashcam evidence was submitted to North Wales police via their Operation SNAP web portal.  The driver and his wife, a passenger in the Honda both gave evidence to support the video evidence at the magistrates’ court and at the appeal hearing at Mold Crown Court. 


On receiving notice that there was to be an appeal North Wales police also received an expert witness statement from a Mr Mark Littler of Littler Winstanley Consultants.  Littler had examined the video file and had made several claims about the integrity of the video file and the circumstances visible in that file.  As a result of the technical challenge to the content of the video, North Wales police sought assistance from RSS so that a response could be made to Littler’s report.


Littler had alleged that the video file had possibly been converted from a 30 frames per second video made by the dashcam to a 25 frames per second video.  As such the timing available in the video file could not be relied upon to make calculations of speed and distances as well as the time available to Roberts to see and avoid an approaching motorcycle narrowly missed by him as he overtook the car with the dashcam.  After challenging the integrity of the video timing, stating it could not be relied upon, Littler went on to make a number of calculations designed to exonerate the actions of Roberts as he overtook and narrowly missed colliding with an oncoming motorcycle and rider.


The picture shows the incident.  The car driven by Roberts leaves a space of only 1.0 to 1.2m for the motorcyclist to pass his vehicle.  Steve Callaghan, technical support manager of RSS, examined the video, the location and the width of the motorcycle and found that there was only between 0.2m to 0.4m of space between the side of the vehicle and the motorcycle handlebar as the two vehicles crossed at a combined speed of 117mph.  


Steve was able to explain to the court that when a video file is converted between formats that the applications making that conversion are constructed to act in a way that preserves, as close as is possible, the rate at which time is reproduced when the video is viewed.  The days of hand-cranked video cameras are no longer with us and having to view films with Keystone Cop motion is no longer necessary.  Steve was also able to use timing techniques to check that the clock, embedded within the video image and recorded at the time of the incident, was being reproduced in real time.  


The accuracy of that clock was better than ±0.03% as was the rate at which the video frames were being viewed in replay mode. 


The speed of the car with the video camera in it, displayed in the video recording, was also checked using distances between marks on the road and the timing produced by the video recording.  The speeds shown in the video matched very closely to those calculated using independent distances and times.  These methods of calculation and checking showed that the integrity of the video recording was acceptable to make calculations of time, speed and distance.  


The court heard that Roberts pulled out to overtake on the A4212 Trawsfynydd to Bala Road as he made his way from Porthmadog to Shrewsbury on October 15, 2017.  When he did that there was a near miss with a motorcyclist, who had never been traced, coming the other way. 


The judge, Mr Recorder John Philpotts, sitting with two magistrates, dismissed his appeal and said that Roberts overtook a Honda on the approach to a blind right-hand bend. 


He said that having pulled out to overtake while approaching that bend, he had not considered that traffic may have been approaching in the other direction.  Roberts had been unable to regain the correct side of the carriageway. Fortunately, the motorcyclist was able to ride through a very narrow gap between the Maserati driven by Roberts and the verge, avoiding "a catastrophic collision."  The judge added that if the oncoming vehicle had been a car, van or lorry rather than a motorcycle then a head-on collision would have been inevitable. The video showed that Roberts made no attempt to brake or to try and avoid a potential collision. 


It was Roberts' case that the manoeuvre was safe and that he could have returned to the correct side of the carriageway had the vehicle he overtook that had the dashcam inside had not accelerated and if another vehicle in front had not braked.  Roberts gave evidence that the Honda CRV had accelerated hard as he attempted to overtake it, the driver of the Honda, he said, was deliberately preventing him passing and hence it was that driver who had caused the danger.  


The evidence given by Steve Callaghan’s careful analysis of the dashcam video showed that the driver who was overtaken had already started to accelerate before Roberts' overtaking manoeuvre commenced and that acceleration was very gentle and had continued for more than 10 seconds.  The rate of acceleration was only just more than 0.03g at the time Roberts passed the Honda CRV and motorcycle.  Littler was challenged about this when giving evidence but he had not made the calculation even though he admitted that the calculation could be done and the result of 0.03g showed the acceleration had not been “hard” as Roberts had stated.


After consideration of all of the evidence, the court decided that the appeal would be refused…Judge Philpotts said  "In our judgement, his driving was clearly dangerous at the relevant time.  The incident must have been terrifying for the motorcyclist. The margin for error must have been very small indeed. It is a matter of the greatest good fortune that there was not a collision”. 


Roberts of Aldersgate Street, London, had been ordered to pay fines and costs totalling £2,425 by the magistrates. The Recorder said that the penalties would stand and that he would have to pay an additional £620 towards the costs of the appeal. 


He was banned from driving for a year and ordered to take an extended driving test. 


Steve Callaghan said that there is a lot of false information circulating among expert witnesses working for defendants.  It is common for false claims to be made about the integrity and accuracy of video information.  Many reports have been seen that attempt to undermine timing and speed information in dashcam video files.  If doubts about timing are raised it is either because of ignorance in the technology or an attempt to dismiss information that can be recovered.  


If video information is challenged, then advice should be sought to determine whether these are genuine or to make a proper forensic examination of the file.  The video in this case of dangerous driving revealed a lot of information that not only assisted in the refusal of the appeal made by Roberts but also showed that his technical advisor was inadequate, Steve added


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