The clip - captured by one of the dashcams in a Highways England patrol vehicle on the M6 - shows how quickly an incident can happen if motorists don’t leave plenty of space between themselves and the vehicle in front.
The footage shows several cars braking sharply and one being struck by a HGV as an unrelated incident unfolds up ahead of travelling traffic.
Highways England’s Head of Road Safety, Richard Leonard, said: “This footage is a startling reminder about the dangers of driving too closely to the vehicle in front.
“It clearly shows that if you get too close to the car in front, you won’t be able to react and stop in time if they suddenly brake.
“We also know that tailgating makes the driver in front feel targeted and victimised, distracting their attention from the road ahead and making them more likely to make a mistake.
“It is intimidating and frightening if you’re on the receiving end. If that leads to a collision, then people in both vehicles could end up seriously injured or killed. We want everyone to get home safe and well.”
The incident happened on the M6 in Cheshire.
If you wonder whether you are ‘space invading’, then remember the Highway Code, which says that drivers should allow at least a two second gap, which should be doubled on wet roads. If you are tailgated, then avoid speeding up, slowing down or staring in the rear-view mirror. Reduce the risk to yourself by driving normally, signalling clearly and allowing people to overtake.
A survey by Highways England reveals that tailgating is the biggest single bugbear that drivers have about other road users. And in-car research - using dashcams, facial recognition, emotion tracking and heart monitors - reveals that a driver’s typical reaction to someone who tailgates them is surprise, anger and contempt, with a spike in heart rate.
Nearly nine out of 10 people say they have either been tailgated or seen it. And more than a quarter of drivers admitted to tailgating.
Highways England has a dedicated website offering advice on how to drive safely if people find themselves the victim of tailgating.