Upset by the recent road deaths across the capital and the way the finger of blame seems to be pointing at them, London cyclists took to the streets to call for greater investment in road safety

On Friday night I had a quick word with my boss (also a regular cyclist) and then slipped away a little early from Kings Place to pedal down Farringdon Road, over Blackfriars Bridge and on to the Transport for London building. As I arrived at 4.50pm there was already a fair-sized huddle of fellow cyclists gathering in the cold around a portable sound system and banner on the pavement.

The quickly swelling crowd was the result of less than two weeks' hectic and quite spontaneous activism by a relatively small group of people, coordinated via Facebook. I had been one of those activists.

On 13 November the London Cycle Campaign organised a protest at Bow Roundabout after the death of a cyclist crushed by a left turning HGV on the CS2 cycle route. When the protesters dispersed two of them decided to go for a coffee. As they sipped their brews Donnachadh McCarthy and Steve Routley mused about what else they could do to raise the profile of the issue and came up with the idea of a direct action protest modelled on those of Dutch campaigners in the 1970s. They thought it would be great if they could get 50 or 60 cyclists to join in.

Donnachadh later explained to me: "I have been a cycling campaigner in Southwark since 1994. I went through the usual political and democratic channels for all those years but failed and have now concluded peaceful direct action is the only thing that will shift the sclerotic transport and planning departments in councils' and mayors' offices."

That night Steve went home, designed a photoshopped image of cyclists sprawled on the ground in central London and the idea took root. The next day a Facebook event page appeared. A couple of days later I came across the page and clicked the button to say I'd attend and so did a friend of mine. She suggested we go out leafletting. I agreed to meet her. The next morning we met up with Donnachadh and Steve at Oval tube station at 7.30am and quickly gave out several hundred leaflets.

A gaggle of other cyclists were doing likewise by key junctions and traffic lights on routes into London. A list of times and places quickly appeared on the Facebook page and then a website too, with a snappy new slogan. Most of us didn't know each other. We just decided to get busy and raise the campaign's profile. Over the next 10 days we handed out thousands of leaflets across the capital.

It isn't a homogenous group and I can't speak for others but our motivation was broadly the same. We were worried and distressed at the news of so many cyclist deaths in the first part of November. I'd already attended several cycle protests organised this year by the LCC as part of its Space4Cycling campaign following earlier fatalities.

We were frustrated at the response from Boris Johnson, who made a series of comments that implied cyclists were to blame for this spate of accidents. Sections of the press inevitably echoed this sentiment.

We felt that the real problem was the lack of cycling infrastructure that puts cyclists alongside HGVs and buses in an inherently dangerous way, especially given the huge blind spots that most HVG drivers have to contend with.

We frequently found ourselves rubbing yellow-clad shoulders with members of the Metropolitan Police as we stamped our feet in the cold, their presence generating not a few comments from fellow cycle commuters.

There was debate, not least with the officers present, about the efficacy of helmets and hi viz tops. The argument on whether to wear a helmet or not is well exercised within the cycling community and shows no sign of abating. Recent studies on hi viz clothing show it has a minimal effect on motorists' behaviour. I wear both but that's a personal choice, it's not the law, and many cyclists are angry at being pulled up by the police over this.

The other issue raised by a lot of the cyclists I leafletted was the way so many cyclists run red lights. The Standard ran a piece the day before the protest about this, though the figures have been challenged.

There is no excuse for people behaving badly or irresponsibly, be they cyclist, driver or pedestrian. However, most campaigners have been concerned not to point the finger of blame at one group or another. I don't know the figures for those killed in London this year who were or were not wearing hi vis and helmets. Nor do I know if they were killed breaking the highway code in some way. And as far as I can see neither do the police.

However, the statistics we do have show that it is far more often the driver rather than the cyclist who is at fault in a collision. My guess is that, like most London cyclists, the majority of those killed probably were wearing hi viz and helmets and probably were not breaking the highway code.

Hi viz will not save you if the lorry driver can't see you because of poorly designed cabs. A helmet won't protect you from a 20 ton lorry or bus's wheels. Abiding by the rules won't help you if there is inadequate provision to segregate cyclists from the heavy vehicles we currently have to commute alongside every day.

As Friday drew near increasing numbers of cyclists I approached said they'd seen the leaflet elsewhere or had signed up on the Facebook page already. There was definitely a buzz in the air.

By 5pm on Friday the crowd outside TfL's front entrance was spilling out into the road. As arranged, the police blocked off the traffic and our vigil commenced with a brief speech followed by a touching musical tribute. Then at 5.30pm we lay down in the road – not 50 or 60 but more than 1,000 of us.

Finally we listened to speeches from Donnachadh, Steve and others including Nazan Fennell, the mother of 13 year old Hope, killed in Birmingham in 2011 by an HGV while using a pelican crossing. We ended the vigil with a reading of the names of London road victims over the last twenty years – pedestrians and cyclists – and a final poignant choral flourish before our demands were handed in to officials at Transport for London, though Boris Johnson's cycling supremo, Andrew Gilligan, was not to be seen.

After two weeks of activity we'd filled the road by Transport for London's offices in spectacular fashion and added our voices to the increasing clamour for substantial and rapid change to London's transport policy and infrastructure. Let's see what happens next.