It took workers in 1963 a single Bank Holiday weekend to rip up Oxford Circus, replace the crossroads with a steel cage, concrete over it, and start excavations for the Victoria line.

I mention this engineering feat because it is now 18 years since the campaign began for urgent safety improvements to the Hornsey Lane bridge.

That’s the same age as the young woman who sustained serious injuries on Sunday when she fell from it.

Readers may well ask how it can possibly have taken so long to build a fence, though most will know the basic history – objections from heritage groups; designs that weren’t sufficiently tall or sturdy; prototypes that didn’t match the plans; three adjoining authorities (Islington, Haringey and TfL) squabbling over who was required or allowed to do what; and so on.

Islington and Haringey finally signed off the stainless steel fence in September, and Haringey was tasked with building it.

Since then? Five long months have passed – and counting – during which another person has now been badly injured.

And the work still isn’t projected to start until the end of March, and will take eight weeks to complete – meaning nearly nine months will have elapsed since it was granted planning permission.

In a big organisation, things take time. There are procedures, legalities, drafts and redrafts, people who must sign things off. And time is needed for the specialist bridge pieces to be manufactured, too.

But nine months, sign-off to delivery, for a set of lifesaving non-structural alterations to a single road bridge is pushing it.

For everyone’s sake I hope this is the last time we have cause to report on the bridge before the fence is physically in place.