Blink and you miss it. Just past the Tot Hill McDonald’s, 20ft above the northbound carriageway of the Newbury bypass in Berkshire, an old oak stands over hundreds of young saplings.

Named Middle Oak by people who lived up it for months in the bitter winter of 1996, it is the only physical reminder of the 35 protest camps built high in the trees on the route of the most controversial new road in recent British history.

Middle Oak was the only one of 10,000 mature trees in the path of the road to be spared and last week it sported a single red ribbon, placed by an unknown person, to commemorate 20 years since John Major’s government started to clear 350 acres of largely protected ancient landscape.

What should have been a simple engineering job taking a few months, ended up costing £74m to build, £5m to police and £25m for the 800 security guards employed to deter the thousands of people who camped on site. There were 780 arrests as protesters resisted everything thrown at them by the state.

Newbury defined the 1990s road protests. Swampy – now a family man living in Wales – was barely there but images of him and other protesters dominated the news in disaffected Britain and attracted thousands of students, the unemployed, former soldiers and idealists.

For the first time possibly since the Romans, roads made headlines.

But 20 years on there is no consensus on whether it ever did relieve congestion, how far it changed thinking about road building and whether a new bypass is needed to cope with thousands of new houses expected to be built close to the road.

Neither Newbury town council nor West Berkshire district council would comment on the road’s effect on traffic flows, but a 1999 government report claimed it had taken heavy traffic away from the town.

“The road was a great success in every sense. Newbury is a much more prosperous place now,” said Nicholas Blandy, a former immigration judge who in 1996 was made under-sheriff of Berkshire, responsible for evicting thousands of people from the site.

A female protester clings to the top of a tree in the path of the proposed road. Tree surgeons working with Bailiffs cut all the branches off the tree underneath her and left her clinging on for over an hour. Photograph: Andrew Testa/Panos

But a 2006 study by the Campaign to Protect Rural England said the bypass barely reduced traffic and caused more fatal accidents.

Today, some local residents say traffic is no better than it was 20 years ago.

“The old road is frequently choked with nose-to-tail traffic. We paid £100m just to move traffic jams up and down a bit of road,” said businessman Adrian Foster-Fletcher.

Rebecca Lush, a protester who now runs the charitable arm of a cosmetics company, said Newbury had changed public thinking on roadbuilding. “It stopped new roads being built for a generation. The Tories had 600 schemes planned. When Labour came in the next year it abandoned the multibillion pound programme. We always knew we would lose the battle of Newbury but we won the war,” she said.

Phil Goodwin, former head of transport at Oxford University, said: “Research has continually shown that road-building generates additional traffic, but the lesson seems to slowly disappear from official thinking, and it is given less and less attention until yet more research brings it back into focus.”

Numerous books and PhDs were written and documentaries made about the protests. But their legacy may be the flowering of a generation of young environmental and political activists, according to Pippa Pemberton, once a Newbury protester and a former inspector of ancient monuments and now a prospective Wales Green party candidate for the Welsh Assembly elections for Mid and West Wales.

“Newbury was a recruiting ground for many groups. You could not go through an experience like that and not be touched by it. It gave people a sense of having a political voice for the first time,” she said.

Theo Simon, a singer with folk group Seize The Day and also a prospective Green MEP, said: “The solidarity, hardship and empowerment we shared sealed a commitment to the welfare of the planet which hasn’t faded. Our momentum and experience went on to invigorate British campaigning culture and shaped our personal lives, too. Many of us are still active on climate, fracking, nuclear and social justice, and all of us know that the battle for sanity hasn’t been won yet.”

This article was amended on 26 January 2016 to correct Green party candidate Pippa Pemberton’s election details.



VOICES FROM THE PROTEST

‘I remember the solidarity’

Ralph Smythe

I was a law student in Oxford at the time. My interest in environmental law developed as did my love of the countryside and belief in non-hierarchical ways of organising. I remember the huge sense of solidarity between so many different people, all united around protecting a precious landscape. Although I had been involved in earlier protests, this time it really felt as if we were about to win. Ralph Smythe is now head of infrastructure and legal at the Campaign to Protect Rural England ‘I was arrested 26 times’ Arthur Pendragon

I was there from start to finish. Once I spent three hours up a beech tree keeping the bailiffs at bay. I was arrested 26 times and was in and out of prison because I refused to pay the fines. I was bloody good in court, and once I was defended by Keir Starmer, the future director of public prosecutions. Newbury made me even more determined to speak out against injustice. I have contested all elections as an independent and taken the government to court over Stonehenge.

Arthur Pendragon, aka King Arthur, is chief druid of the Loyal Arthurian Warband

‘I was going to be an eco-warrior’ Martin Porter

I arrived at Newbury and was directed to Granny Ash camp, through the snow in the dark. It was mad. No more evenings writing letters for Amnesty for me, I was going to be an eco-warrior. The next year the spotlight moved back north to Manchester Airport and I was there, first up a tree, then down a tunnel. Many have dropped out of frontline protesting, but we’re still around, still radical.

Martin Porter is now a social worker

‘We used to take them hot food’ Janet Griffin

I was working as a PA in a Newbury solicitor’s office. We never liked the road, they took it through the prettiest bits of countryside. We never had a car and this was where we went for picnics. The protesters were so young and living in appalling conditions. They became our adopted children. We used to take them hot food in that wicked winter. I used to go up to Go-Tan, Spiritual Roots and Brian the Snail camps and throw Mars bars up into the trees. Some were too young to go to prison. I missed them so much when they left, I cried.

Janet Griffin, now 80, runs an environmental group, Local Voices

Photograph: BBC

‘I didn’t take it personally’ Nicholas Blandy

I was the Berkshire under-sheriff. It was my responsibility to evict people. They had a big sound system rigged up in the trees playing Bob Marley’s I Shot The Sheriff, which was funny. Everyone used to shout at me but I never saw it as personal hatred. The protesters were mainly gentle and I had considerable sympathy for them. It was unbelievably cold. The law was done and seen to be done with conspicuous gentleness. My bailiffs and climbers were met with urine and had shit thrown at them. The protest set me on a path of change. I could no longer stand day after day sitting at the office doing conveyancing work. I became an immigration judge.

Nicholas Blandy has retired

Photograph: Handout from CPRE