London Street in Norwich was pedestrianised on 17 July 1967.
The pedestrianisation of Norwich city centre is often referenced by fans of the fictional DJ, played by comedian Steve Coogan.
The Norwich Society said the city had "pioneered pedestrianisation in the UK".
Alan Partridge posed the question "what do you think about the pedestrianisation of Norwich city centre?" during an intimate scene.
In the episode from 1997, Partridge said: "I'll be honest, I'm dead against it. People forget that traders need access to Dixons.
"They do say it will help people in wheelchairs."
Norwich City Council approved plans to pedestrianise more parts of the city in 2015.
Paul Burall, vice chairman of the Norwich Society, said: "Norwich pioneered pedestrianisation in the UK and continues to extend the benefits, with another two streets being pedestrianised in the last two years.
"While a few local people agree with Alan Partridge and still want to be able to drive everywhere, the vast majority welcome the ability to walk around without the noise, pollution and potential danger from traffic, and the great majority of traders recognise the benefits as well."
Norwich is far from being the only town or city whose profile has been raised by its television connections.
During the pedestrianisation ceremony, the then Lord Mayor of Norwich CH Sutton tied - rather than cut - a ribbon across London Street to signify its closure to traffic.
Although other shopping areas - such as those in new towns like Stevenage - were made pedestrian-only long before London Street, the Norwich road was the first to be closed to motorised traffic and given over to pedestrians.

Leah Washington had her leg amputated after two carriages on the Smiler ride collided on 2 June. Three others suffered severe injuries.
Merlin Entertainment said it had contacted those injured and all 16 on board would receive compensation.
Lawyer Paul Paxton, representing three of the families, welcomed the decision.
Ms Washington's boyfriend, 18-year-old Joe Pugh, from Barnsley, is being treated for two broken knees and "extensive" hand injuries at the Royal Stoke University Hospital.
The couple were in the front row of the Smiler ride, alongside Daniel Thorpe and Vicky Balch, when it hit an empty carriage.
Twenty-year-old Ms Balch, from Leyland in Lancashire, has undergone surgery in Stoke and is said to be in a serious, but stable condition.
Mr Thorpe, 27, from Buxton, Derbyshire, is being treated for a collapsed lung and fractured leg at a hospital in Coventry.
Chanda Chauhan, 49, from Wednesbury, who was sitting in the second row of the Smiler, was also admitted to Walsall Manor Hospital with internal injuries.
Merlin Entertainment, which owns Alton Towers, said it had hand-delivered letters to all of those affected.
Last week, chief executive Nick Varney promised there would be no problems with compensation and that those injured would "want for nothing".
Alton Towers reopened to the public on Monday, but the X-Sector area, including the Smiler, remains closed.
The two carriages that collided have been removed by the Health and Safety Executive to be examined in a laboratory and investigations are continuing at the theme park itself.
A city whose traffic plans were made famous by Alan Partridge is marking 50 years since one of its roads became the first to be pedestrianised in England.
[NEXT_CONCEPT]
Lawyers representing the families of those injured in a rollercoaster crash at Alton Towers have welcomed a promise of compensation.