Barrier damage is measured, photographed and matched to a reported collision, because somebody pays for it. One run gets a fresh impact three or four times a year with no collision on the system, and the paint transfer comes back as a colour that stopped being made in 1987.
I am a barrier inspector for a maintenance contractor. Twenty two years, and I have measured more steel than most people have driven past.
How damage gets recorded.
You walk the run with a string line and a rule. A tensioned corrugated beam sits on a surveyed alignment, and an impact pushes it back, and you measure the deflection at each post and grade it. Grade one is cosmetic, grade three needs replacing.
Every damage record goes on the system with photographs, chainage, and a note of the incident it belongs to. Our control room logs every reported collision, so the two lists get matched and the repair is billed to an insurer.
An unmatched damage is not unusual on its own. People hit a barrier at two in the morning and drive away.
The same thirty metres, at the same chainage, on a straight, gets a fresh impact three or four times a year.
Since 2011, which is when I took this contract on.
The impact is real and it is always the same shape.
Deflection of between two hundred and three hundred millimetres, over four posts, with the beam scored along the top corrugation and the two centre posts bent back.
That is the signature of a vehicle hitting a barrier at a shallow angle at speed, which is what the barrier is for, and it is what we repair perhaps two hundred times a year across the region.
What is not usual.
There is no reported collision. Not once in fourteen years, and this is a lit section with cameras on it and a control room, and every other impact of that size on my patch is in the log.
There is no debris. An impact of that scale leaves a wing mirror, a light lens, a piece of trim, and usually a lot of it. There has never been anything at that chainage but the barrier.
And there is paint on the beam.
The paint.
Paint transfer is the ordinary way you get somewhere with a hit and run: a fleck of it goes to a laboratory and comes back with a manufacturer, a range and usually a set of years.
I have sent four samples in fourteen years, through the police the first time and privately the last three because the police, quite reasonably, have nothing to investigate.
All four reports say the same thing. It is a two pack acrylic in a mid blue, of a formulation consistent with a British manufacturer's fleet range, and the last report names the range and says it was withdrawn in 1987.
The most recent sample went in last year, off a beam that was undamaged on my previous inspection eleven weeks before.
What has been done.
The run was replaced entirely in 2016. New posts, new beam, new terminal, on a slightly revised alignment because the standard had changed.
It happened again in the March.
The cameras. I have asked the control room for footage on four occasions. Twice there was none for that period. Twice there was, and I have watched both, and the barrier is undamaged in the last frame of one night and damaged in the first frame of the next morning, and in between the camera is looking at an empty motorway in the dark and nothing goes near it.
What happens about it.
We repair it, and it goes on the system as an unmatched damage, and the cost goes into the general maintenance budget because there is nobody to bill.
Three or four repairs a year at that chainage is a few thousand pounds and it has never been queried by anybody.
What I do.
I inspect the run on the cycle like everything else and I write down the numbers.
The one thing I have changed is that I take the string line from the north end now.
You measure a deflection by running a line along the undamaged beam either side of the hit and reading the offset at each post. Which end you start from makes no difference at all to the number.
I started at the south end for eleven years because the lay-by is at that end and it is a shorter walk with the kit.
In 2022 I was working north with my back to the traffic and my hand on the beam feeling for the score line, which is how you find the extent of it when the light is flat.
The steel was warm under my hand for about four metres, in November, at eight in the morning, on the shaded side of the road.
I have taken a thermometer to it twice since and both times it was the temperature of the air, and I have never once put my hand on that run again.