Driving a London cab has long been a tradition in Jewish families — a legacy passed from grandfather to father to son and sometimes daughter (although 90 per cent of cabbies are men). So the news that Maureen Lipman is directing the stage premiere of her late husband Jack Rosenthal’s 1979 tour de force television play The Knowledge at the Charing Cross Theatre has been greeted with an enormous roar of affection for a lady that the London cab trade think of as one of their own.

It’s been 13 years since her husband died. Lipman is now “thrilled, excited and full of trepidation” about reviving this iconic play which follows four Londoners as they attempt the fearsome “Knowledge” — the process of becoming a London black-cab driver.

Lipman is a self-confessed black-cab nut who still remembers occasions when she came home to find Rosenthal playing host to a random assortment of cab drivers in his quest for absolute authenticity and perfection. Did he achieve it? Just stop any cabbie and ask. They will instantly recall the way in which Rosenthal captured the very essence of The Knowledge with an examiner nicknamed “The Vampire” for his exacting standards and heavy irony.

The idea to bring the play to the stage came from Vaughan Williams, chairman of the Charing Cross Theatre, a prolific black-cab user who lives just a few metres from Gibson Square, destination of the very first run on the very first page of The Knowledge’s essential Blue Book. Having got Lipman’s approval, two years later — with the script adapted by Simon Block— she accepted an invitation from Williams and his co-producer Steven M Levy to direct the show.

Lipman’s face, so mobile and humorous, belies her 71 years. She’s been busy working all over London — at the Hampstead Theatre, pantomime in Richmond and a stint at the Menier Chocolate Factory in Southwark.

Completely at home in the cramped confines of a black-cabbie café, dressed in smart cream chinos and navy sweater, she asks what’s good to eat.

“Salt beef, of course,” yell a dozen different voices. A stream of passing cabbies come up to say hello as word gets around just who is paying the café a visit. Lipman proves quite happy to join in with rants about congestion, cycle lanes and Ubers, which she abhors and will not consider using.

Drivers compete with each other to recall the times they’ve picked Lipman up, driven The Knowledge crew home, or helped Rosenthal with his research, while Lipman, with Williams hovering alongside, serenely drinks her coffee and grins at the one-upmanship she can hear.

“It’s been a terrific challenge adapting Jack’s play to suit the limited stage at the Charing Cross and choosing which characters to focus on, but I hope that, between us all, we’ve got the mix right,” she says.

“Obviously, some characters won’t work on stage but Simon Block, who adapted Jack’s play, has kept nearly 80 per cent of the original dialogue, and I just love his script.”

Having my own cab driving dynasty: an ex-husband, current husband, son, countless cousins and uncles, I once felt compelled to sign up as a Knowledge Girl myself. I failed miserably — map-reading was a closed book to me. Would Lipman have done any better? She laughs. “I may not have the world’s greatest sense of direction, but there are similarities between acting and doing The Knowledge.

“At drama school, we stand there calling a script over to each other every day for months until we know it backwards. Then we have appearances in front of several examiners. When we’ve done that a few times at harder and harder levels, if it’s gone well, we get the chance to act for a living!”

She’s fully aware of the many challenges facing London’s cabbies. And, as a member of the capital’s cabbie community I can confirm that we see the revival of The Knowledge as part of the fight-back against the many problems we face.

The love that cabbies feel for her is clearly returned. “Despite huge changes in technology, competition, regulation and driver diversity, the rigorous training of The Knowledge remains intact,” she says. “Somehow, that process continues to produce some of the most charming and entertaining people I ever meet!”

‘The Knowledge’ is at the Charing Cross Theatre, September 4 to November 11.