Ask any urban cyclist about "taking the lane", and even if they haven't heard of the term, they have probably done it. Although widely regarded as safe practice, this often gets negative responses from other road users. So who is right?
"Taking the lane" or taking "primary position" is essentially riding in the centre of the lane. Cyclists do it a) when passing parked cars whose doors may suddenly open; b) to prevent traffic overtaking dangerously in narrow roads and c) when manoeuvring or turning.
London cycle blogger Sam wrote recently how a taxi driver threatened him when he "took the lane" in a narrow street. Sam was told by police officers he shouldn't have been riding in the middle of the lane.
In the same week Hannah Widmann, a 26-year-old London student, took "primary position" at traffic lights when a driver behind started using her horn. Hannah said: "When I pulled left [from primary position] after about 25m, she had lowered her windows and her kids were screaming at me, using incredibly offensive terms."
Taking the lane is recommended by government-approved cycle training scheme Bikeability, because cyclists are safest where they can see the road and be seen. If in doubt, primary position should be the default road position.
Section 163 of the Highway Code states road users should: "Give motorcyclists, cyclists and horse riders at least as much room as you would when overtaking a car."
David Dansky, head of training at Cycle Training UK (CTUK), said:
"The guidance we give cyclists is to take the space they need.The potential hazard is that drivers behind might not understand what you are doing.
The courteous thing when you are riding in that assertive position is to look behind you and make eye contact. You still get drivers who don't understand, but as more and more people get on their bikes you get more understanding from drivers.
"A bicycle is a vehicle on the road and a person riding it has the right to act like any other person on the road.We all hear of cases where someone gets too close to the left and there are very unfortunate consequences if a lorry driver doesn't see them.'Some motorists think it is a divine right to be moving at whatever speed they want and a cyclist is holding them up. I'm afraid it is tough if a cyclist holds them up. In most urban areas traffic moves slowly so a cyclist doesn't hold up traffic."
In years of personal experience riding in cities I find eye contact invaluable in maintaining a safe position on the road, though it doesn't placate all drivers or eliminate the risk of aggression.
In a post on London Fixed Gear and Single Speed forum (LFGSS), Dansky said:
"While I believe that this ['punishment' by drivers] is transitional and a reaction to a change in road hierarchy by drivers who are losing their dominance, there is a need for local government ... and driving organisations to start encouraging this acceptance with images of cyclists riding assertively and words legitimising this."
In 1998 CTUK produced a document for police in response to feedback from its instructors where in one training session the following happened: "The policeman watched the session for a while and came over and said: 'Why are you teaching them to ride in the middle of the lane, they should be riding over on the left?' "
As the instructor pointed out, this would have put riders in the "car door zone".
London cyclist James Russell was passing a row of parked cars in east London earlier this year when he was pulled over by police.
"I was told: 'You need to move over more' and I said I didn't. The officer made a sarcastic remark before she left shaking her head," he said.
London Cycling Campaign's Mike Cavenett said:
"Most London cyclists will have experienced ill-informed motorists who think we're being arrogant or selfish when all we're doing is taking a safe, government-approved road position. It can be extremely intimidating and dangerous to have an angry motorist behind you trying to overtake.The fact that even some police officers don't understand the concept shows how vital it is that a cyclist's right to take the lane is enshrined in the Highway Code."
Chief inspector Ian Vincent, Cycle Task Force, said:
"There is no specific Metropolitan police service guidance on cycle safety. We refer cyclists to the Highway Code and Transport for London's (TfL) cycling safely page, which recommends cyclists ride assertively, away from the gutter. If the road is too narrow for vehicles to pass you safely, it may be better to ride in the middle of the lane to prevent dangerous overtaking."
The Highway Code, however, doesn't mention primary position at all.
In an attempt at clarification a Department for Transport spokesman told me Bike-ability cyclists are trained to manage risk and use their own judgement based on the road conditions.
Cycle blogger Sam told me:
"I cycle around 12-15 miles a day and often take the lane - sadly on some roads it's the only way to prevent being overtaken too fast and too close.
It causes problems because drivers think you're being actively hostile. We have these weird 'assertive' cycling styles - 'taking the lane', 'primary position' - but the only people who know about them are cyclists (and only a minority of us).
Sometimes I'm in a car with my mum and she says things like, "that cyclist has a death wish", when actually they're cycling correctly."
While writing this blog I "took the lane" on an east London road as a lorry approached in the other direction. The driver behind overtook anyway, passing within 30cm of my front wheel while honking his horn.
At the lights I asked the driver whether he had hoped to run me over. In response he stared straight forward as the passenger side electric window wound up in my face.
• Laura Laker is a cyclist and freelance writer/ source The Guardian.co.uk