In two years he's been sworn at, threatened and nearly killed on the road

Adds that ‘people can't go three seconds without checking Facebook or Twitter feed...It’s madness'

Dave Sherry films drivers breaking the law on his helmet camera

Hurtling towards the traffic lights, the young mother has already picked up her mobile phone and is tapping out a text. Her baby daughter is gurgling away in the child seat, but mum is dangerously oblivious to everything around her.

A twentysomething boy racer follows not far behind, chatting away on his smartphone as he speeds along.

A few minutes later, another young woman tries to send a surreptitious text from the phone in her lap. She’s got two children in the back, but seems blissfully unaware of the danger to them.

During rush hour on a busy A-road near Harlow, Essex, plenty of drivers are fiddling with their handsets rather than concentrating on the road ahead.

Most of us, motorists or pedestrians, have encountered such irresponsible driving on countless occasions — but tonight someone is holding them to account. Step — or rather pedal — forward Dave Sherry, cyclist and self-styled scourge of reckless drivers, who is capturing footage of their misdemeanours on a camera attached to his bicycle helmet.

At the first hint that someone isn’t driving responsibly, 37-year-old Dave heads in their direction to confront the culprit. If they express no remorse — they rarely do — he sends the footage to the police.

He’s not alone, either: aided by sophisticated cameras attached to their dashboards or their bike helmets, a growing number of motorists and cyclists are taking on law-breaking drivers in an attempt to make our roads safer.

Their first port of call is Police Witness, a private company that sifts through footage sent in by the public, assesses whether a crime may have been committed, and if so, sends it on to police forces throughout the UK. On average the firm receives up to 100 pieces of footage a week.

Dave is one of their regular contributors. A cheerful father of five — he has four children, Matthew, 11, Rebecca, eight, Tyler, three, and one-year-old Emily by his wife Leanne, and Morgan, 16, from a previous relationship — his mantra is ‘prevention is better than cure’. That, and ‘zero-tolerance for drivers using mobiles’.

For the past two years, Dave has recorded footage on his sophisticated £350 helmet camera as he makes his way by bike during rush hour from his Essex home into East London where he works as a bus driver.

Footage from Dave's camera shows a driver talking into a mobile phone while behind the wheel

During that time he’s uploaded footage of hundreds of motorists onto his home computer, which he sends on to Police Witness. As a result, more than 60 offenders have received cautions, fines or points on their licence.

On one record day Dave caught 20 offenders in four minutes. Tonight, however, I am joining him to cycle around the roads near his home to give me a snapshot of the sort of things he sees day in, day out.

You don’t have to wait long to catch someone breaking the law.

‘You look for the tell-tale drift,’ Dave tells me. ‘They veer from one side of the road to the other, and they’re so busy chatting they have no idea they’re doing it.’

And on the busy A-road out of Harlow town centre, plenty of them are at it. Like the boy racer cruising past at speed, chatting away on his smartphone.

On one record day Dave caught 20 offenders in four minutes - he says that people 'cannot go three seconds without checking Facebook or Twitter feed...It’s madness'

We follow in hot pursuit, aware we’ll easily catch up with him as the traffic lights ahead are about to turn red — and where, when we reach him, the twentysomething boy receives a toot from a thunderously loud red horn attached to Dave’s handlebars, a device he jokily refers to as ‘the pacifier’.

The lad winds down the window, allowing Dave to point out that he’s endangering lives by talking on his phone while driving at up to 40mph. Alas, the message falls on deaf ears.

The response is a robust V-sign and a swift acceleration into the sunset. ‘I’ll make his night later when I pass the footage to Police Witness,’ says Dave.

The driver’s indifference comes as no surprise to Dave, who admits few people respond well to a ticking off from a stranger.

‘I’ve been sworn at, called all sorts, threatened. Once I hit a pothole as a van came by so closely that I nearly fell into it. He could have killed me but instead of apologising the driver slammed on his brakes and got out screaming and shouting before shoving me to the ground so hard I was off work for four weeks with a bad back,’ he recalls.

‘At least because it was caught on camera the man got a police caution for the assault.’

When Dave began filming his journeys, he had no idea of the tricky situations they would get him into. His personal campaign to make the roads safer began when a bus driver using a mobile phone came dangerously close to Dave and one of his young children as he pedalled along a road near his home.

Dave has captured all kinds of motoring lawbreakers, from speeding motorcyclists on a pedestrian footpath to a taxi driver taking a blind bend at speed while drinking coffee

Days later, another driver veered into him, buckling the rear wheel of his bike, making him fall off. He wasn’t hurt, but it shook him up.

‘I took his number plate and called the police, but when they showed up they said it would be my word against his so there wasn’t much point in taking it any further. That’s when I resolved to do something about it.

‘I knew footage of an incident was very important if a case made it to court, so the only solution was to get a portable camera to film my journey. When I Googled “Helmet Cams” I found the Police Witness website.

‘I realised they were compiling footage of drivers breaking the law and was keen to contribute.

‘I bought my first camera from them for £100 two years ago, and things snowballed from there.’

Dave has captured all kinds of motoring lawbreakers, from speeding motorcyclists on a pedestrian footpath to a taxi driver taking a blind bend at speed while drinking coffee.

He veered so far into the right hand lane that a had a vehicle been coming the other way a head-on collision would have been inevitable.

Mobile use, though, is Dave’s bete noire. ‘The thing that upsets me most is people with kids in their cars. They are risking all their lives.’

The young mum we see texting at the wheel of her moving car with her baby in the back is a case in point. She responds to Dave with a blank stare when he draws alongside her at a red light and remonstrates with her about using her phone.

‘Her footage is getting sent in,’ says Dave. ‘All she needed to say was “Sorry mate, it’s a fair cop” and I’d have let it go. If people seem remorseful then I give them a fair chance. But if not, they deserve what’s coming.

For the past two years, Dave has recorded footage on his sophisticated £350 helmet camera as he makes his way by bike during rush hour from his Essex home into East London where he works as a bus driver

‘It’s pathetic. I see it time and again. Of course if something happens, they’ll be remorseful and devastated.’

Few, it must be said, offer their apologies during the evening I spend with Dave.

In half an hour, standing by the roadside near a busy roundabout, we count ten drivers talking or texting on their mobiles.

According to Road Safety organisation RoSPA, endless tests have shown that mobile phone use is a significant distraction while driving, with drivers four times more likely to crash if they are using one.

Such grim statistics are what drove businessman Matt Stockdale and former Northamptonshire Police assistant chief constable Alan Featherstone to set up Police Witness three years ago.

This private company sells ‘dashcams’ — dashboard cameras — ranging from £190 to £390, and sifts through footage sent in by the public to see if an offence may have occurred before passing it to police.

People cannot go three seconds without checking Facebook or their Twitter feed. It’s madness - Dave Sherry

‘The advent of mobiles and social media has had a devastating impact on the way we drive.’ Stockdale says. ‘People cannot go three seconds without checking Facebook or their Twitter feed. If they stop at a red light the phone is out and they check their messages and then start replying as they set off again. It’s madness.’

At first the police were not convinced about Police Witness. ‘Their attitude was, “We’re the police, you’re the public, leave this to us.” It took a long time to get the idea of collating footage and sending it to them off the ground,’ he says.

‘Now their attitude has changed. They know they haven’t the manpower to police the roads. They also get a lot of complaints they can’t pursue for lack of evidence. Now we are changing that.’

Certainly, the police are expanding their capacity to receive and act on video evidence sent in by the public: earlier this year, the Association of Chief Police Officers said it is working with the Home Office to improve how digital evidence is processed by police forces. This will make it easier for the public to send it to them directly — something they would not have countenanced a few years ago.

Former deputy chief constable Paul Marshall who has worked with the forward-thinking National Policing Lead for Digital Evidence, has said: ‘The public are in a strong position to provide digital evidence. They need to be able to share it with the police service. You are likely see significant developments in this regard.’

Now Matt is working on an App that will allow users to stream video evidence directly to the police, who can then act as they see fit.

He says: 'I’ve been sworn at, called all sorts, threatened. Once I hit a pothole as a van came by so closely that I nearly fell into it. He could have killed me'

Submitting such footage is already familiar to Kathleen Kirkland, a 41-year-old driving instructor in Milton Keynes. Married with a six-year-old son, she has uploaded videos to Police Witness in the past couple of years, after installing a camera on her dashboard, for self-protection and also as a learning tool for her students, who can view the footage to see examples of bad driving.

‘I’m on the road eight hours a day five days a week, so there is a higher chance of me getting caught up in something — if you do and it’s on camera you can’t argue with the footage. In one lesson I don’t have enough fingers and toes to count the incidents I see.

‘I could spend all day uploading footage, there is so much, so I try to be selective.’

The incidents include: people driving around mini-roundabouts the wrong way, pulling out from junctions without looking, jumping red lights, and, of course, using mobile phones.

‘I’ve seen it umpteen times: someone will veer towards me from the other side of the road, then they look up and I can see they’re texting. I’ve seen people driving on the fast lane of the motorway on their mobiles. I recently filmed a woman parked on zigzags outside our local school for 20 minutes while she had a phone conversation. You’re not even meant to drop off there, never mind park up.’

I’ve been sworn at, called all sorts, threatened. Once I hit a pothole as a van came by so closely that I nearly fell into it. He could have killed me - Dave Sherry

She points out that many people don’t know the law. ‘They think the law on mobile use only applies when they are moving, so they assume it’s okay to pick it up and talk on it at traffic lights. It’s not.

‘The law says a person is still driving while the engine is running and the vehicle is stationary.’

Kathleen is shocked by how widespread careless driving is. She says: ‘It’s not a particular demographic: it’s teenagers, it’s pensioners. Everyone does it. When they climb behind the wheel they feel like they’re in a fortress. Everyone thinks, “I won’t kill anybody.”

‘If I can do my bit to get the message out, why not? It might help make the roads safer.’

Still, while no one approves of people breaking the law, not everyone approves of civilians getting embroiled in work that traditionally involves the police.

‘I can see why,’ says Kathleen. ‘But there are just not enough officers on the road to catch people. I don’t see myself as doing the police’s job. I’m just a witness gathering evidence. What the police then do with it is up to them.’

Back in Harlow, despite our both wearing high visibility jackets as we cycle, I’ve lost count of the number of cars thundering past at speed.

One is so close it almost knocks me off.

Dave clearly feels that it proves that he and other ‘video vigilantes’ have a role to play in keeping roads safe. He says: ‘In an ideal world, there would be no need for these cameras. But we don’t live in an ideal world.