AS readers will be well aware, Hatfield Tunnel is undergoing a two-year refurbishment project. Since July, the northbound A1(M) tunnel has been closed to all traffic. Our chief reporter Kelly-Ann Kiernan was given a behind-the-scenes tour of the north bore and could see first-hand the improvements.

DRIVING through the dark and dingy southbound tunnel at 40 miles an hour with the morning commuters was a stark reminder of the disruption the two-year refurbishment project is having on Times Territory.

The slow slog of cars and drivers wading through the speed restrictions makes you question why was the closure necessary and, more importantly, why is it taking so long?

As we looped around junction three and re-joined the A1(M) travelling north the answers began to become clear.

As I walked through the north bore the most notable thing was how light it looked.

But this was more than a lick of white paint.

The entire tunnel, except the road surface, was stripped back and replaced.

The emergency escape doors have been lowered to ground level, to ease the way for disabled or elderly people, and to comply with the Disability Discrimination Act.

The fans and lights have been changed and most impressively the whole tunnel has been rewired. Highways Agency project manager Eamonn Colgan explained the two systems were running parallel and switching over stage by stage.

He said: “It’s like trying to fit a new kitchen while using it every day.”

Enough cable to travel twice round the M25 is being used to keep the tunnel powered.

Our tour also encompassed a visit to the tunnel’s substation within the Galleria’s car park.

Housed here, as they have been since the tunnel was officially opened by the Duke of Kent in December 1986, are more than 1,000 batteries (similar to car batteries), which, should the power fail, kick in to give two hours back-up electricity.

Also on the site are the security team who are monitoring junctions two to five, 24 hours a day, to keep the traffic moving.

Skansa Balfour Beatty project manager Duncan Thompson said: “We’ve had very few incidents throughout the work so far.

“An elderly couple’s car caught on fire, but helpfully they drove out of the tunnel, before escaping.”

But he added that more than 1,000 drivers a month are still exceeding the speed limit.

Although set to raise around �1.5m throughout the length of the project, Mr Thompson said it wasn’t a question of raising cash.

He said: “It’s about the safety of my staff and other drivers, they are putting other people’s lives at risk.”

The tunnel project is running on time.

The northbound carriageway will reopen in May, when traffic will switch into the tunnel.

The southbound bore will then close until March 2011, with the tunnel back to normal in April 2011.