Women cyclists make up a far higher proportion of deaths involving lorries than men. Why?
Many of the fatalities involving cyclists happen in collisions with a heavy goods vehicle (HGV). This year, seven of the eight people killed by lorries in London have been women.
Considering that women make only 28% of the UK's cycling journeys, this seems extremely high.
There are no national figures but there's little reason to think it is any different. In August, a 27-year-old woman died in Leeds after her bike was in collision with a lorry.
These deaths could be attributed to a tragic anomaly, but some cycling campaigners are concerned whether there is something about how women cycle which puts them at greater risk from lorries.
"It's something we're trying to understand. When you look at HGV accidents there are a lot more women involved than you would expect. We don't know why that is," says Charlie Lloyd, from the London Cycling Campaign.
With this in mind, his group has organised a special women-only bike ride to the Cycle Show in London's Earls Court this weekend, a trip that ends with the chance for participants to sit in a lorry and experience the view drivers have of the road.
The high incidence of women killed by lorries has come to the attention of the authorities before.
In 2007, an internal report for Transport for London concluded women cyclists are far more likely to be killed by lorries because, unlike men, they tend to obey red lights and wait at junctions in the driver's blind spot.
This means that if the lorry turns left, the driver cannot see the cyclist as the vehicle cuts across the bike's path.
The report said that male cyclists are generally quicker getting away from a red light - or, indeed, jump red lights - and so get out of the danger area.
But could it be a matter of confidence? Some women don't feel safe on their bikes and nervous cyclists could put themselves in danger, says Wendy Johnston of sustainable transport charity Sustrans.
Safety is the prime factor stopping women from getting on their bikes, she says, so her organisation is leading a campaign called "Bike Belles" to promote women's cycling, including a petition calling for the government to promote safety.
Feeling nervous about cycling can influence the way people ride, she says. Some women tend to cycle too close to the pavement as they want to stay as far away from traffic as possible.
"This can be a problem as vehicles may not regard you as part of the traffic flow and don't give the right amount of space. It means they may be tempted to come closer to you," says Mrs Johnston.
"It can have an impact on how other vehicles treat you. It can also impact on confidence as if they come too close, as it makes you feel you can't come out in the road."
While many cyclists are calling for more cycle lanes to make their journeys safer, others dislike them because they believe they encourage people to ride down the left-hand-side of large vehicles and towards the kerb.
Marian Louise Noonan, 32, from south London, is a confessed kerb-hugger, and that leaves her feeling quite vulnerable on the roads, unlike her husband.
"He cycles much more aggressively and is aware of all the traffic around him. He cycles as if someone is going to hit him and makes sure he is in a safe position," she says.
"I'm much more nervous of my cycling ability, I'm frightened people might hit me, which means I don't cycle in a positive manner."
The main problem is the attitude of other drivers, she says, as they make her feel like she does not belong on the road.
She also feels reluctant to put herself at the front of the traffic at red lights, which is the safest place for cyclists to be.
"Things like being able to sit in the boxes at the front of traffic lights are safer for someone like me, because it takes a bit more effort to move off and get to the correct speed, but sometimes that annoys other drivers as it looks like you're pushing in."
Ms Noonan's reluctance to assert herself is typical, says Dr Dave Horton from Lancaster University, a sociologist who has written a study on the fear of cycling.
"Being highly visible in public spaces is something women are going to be less comfortable with than men, especially in the road environment in marked areas where people can see you and male drivers can see you.
"There's a discomfort around putting yourself on display. It's the idea that in a car it's much harder to see you."
Turning right is also a problem for some women cyclists because they lack the confidence to look over their shoulder and judge when to cross the traffic, says Ian Walker, a professor of traffic and transport psychology at the University of Bath. He drew this conclusion after studying 5,000 cyclists in Oxford and Cambridge.
But he challenges the notion that nervous cyclists are generally more vulnerable because if fear is visible it can help, he says. The more confident you look, the closer the cars get, he says, and a deliberate wobble is sometimes used by cyclists to get more space.
In one experiment, he cycled with a device which measured how much room cars gave as they passed, then repeated it while wearing a long female wig. Drivers gave the "woman" more room.
Setting lorries aside, the bigger picture is that far more men are killed on their bikes. In 2008, 84% of the 115 fatalities were men and 81% of reported injuries were to men.
And overall, the number of cyclists killed in Britain has fallen by 27% compared with the mid-1990s. Last year, 115 cyclists were killed on the roads, a 15% fall from 136 deaths in 2007.
Two of the women recently killed were experienced, so it's not just about nerves, says Chief Inspector Graham Horwood of the Met Police Traffic Unit.
"It's often that they are in the wrong place at the wrong time and circumstances get to a certain point where they end up in these positions.
"You can't always blame the cyclists and you can't always blame the lorry drivers, it's a mix of who's responsible."
Confident female cyclists like Jane Hornsby, 49, from Oxford, says it's not just safety that puts some women off getting on two wheels.
Practical issues like changing facilities and bringing a spare outfit also play a part.
Women may also have less time than men, she says, because they tend to have the responsibility of looking after children before and after work, and are often carrying shopping.
Below is a selection of your comments.
This article touches a nerve with me. I am an experienced and confident cyclist, but am uncomfortable about cycling past stationary traffic to get to the front at traffic lights. I've had cars pull out to prevent me getting past. I've also experienced road rage where someone (a female passenger) opened her window and screamed at me for daring to be in the right-hand lane in a one-way system. (I was about to turn right.) I've also had a car go past me so close on a left-hand bend that they've touched my wheel. One-way systems are a menace here for cyclists, as are traffic calming measures that force you on to the opposite side of the road into the path of on-coming traffic. My work does not have showering or changing facilities, which doesn't stop me cycling to work, but makes life more difficult.
Anne Lincoln, Maidstone, UK
My brother was killed four weeks ago whilst out cycling. He who used to be a semi-professional cyclist and so was very experienced and not nervous. He was wearing all the right clothing etc. The motorist that ran him down did not give him enough room. His life was cut short and it is extremely heartbreaking for all who knew him.
Lynne Danieli, Middlesbrough
Women are more at risk because they tend to obey the rules of the road - i.e.. stopping at lights and actually riding on the road. I see so many big butch men riding on the pavement like frightened rabbits, it really irritates me. I always ride on the road unless there is a cycle lane, and I always ride well out from the curb, then at least I've got space to fall out of the car's way if it hits me. But mostly, cars just don't give cycles enough room - always trying to squeeze past instead of waiting a few minutes until it's safe to pass.
Elaine Smith, Somerset
I am a keen cyclist and I do think that it is important to be assertive when cycling in traffic. The key to safety is visibility. The diagram of the lorry and the cyclist at traffic lights is very telling. Also, cycle lanes leading up to traffic lights are best ignored for the reasons stated in the article - visibility.
Nicolas Werner, Hove, UK
It is not red light jumping which makes men safer at traffic lights, it is the fact that they are more likely to be in a primary position (ie in the middle of the traffic lane) when waiting at the lights. This means that following drivers are far less likely to overtake and turn left. It is this overtaking and turning left by drivers that cause fatalities, not cyclist filtering down the left side of the HGVs. Cycle lanes are not the solution, they are often badly designed and put cyclist in more danger. There should be Advanced Stop Lines at all traffic lights and ALL driver should know and obey Rule 178 of the Highway Code.
Casual observation suggests that women cycle more cautiously and are thus perhaps more likely to wait inside rather than outside at lights, and similarly might be less likely to nip away smartly. A quick inside getaway might put the cyclist back into the drivers's field of view. thereby decreasing the risk of accident. Maybe not? Nice little research project here with potential big safety benefits as outcome.
When I did my motorbike training, we were told to not hug the kerb because doing so would encourage drivers to try and squeeze past. If they don't make it, they pull in and, as you are right up against the kerb, you have nowhere to go. Hold your road position and make cars/lorries overtake you properly. If they can't, they'll just have to wait. I also use this philosophy when cycling and I always try & position myself where car/lorry/bus drivers can see me.
Sally, Hullbridge Essex
Cycling has become more and more dangerous. Motorists, particularly during rush hour, are often distracted or bad tempered and tend to take more risks. Coupled with these modern cars which have very fast acceleration combined with strengthened bodies I am thankful that there hasn't been an increase in cyclist fatalities. In my city there is a severe lack of cycle lanes, and when there is a cycle lane, it is either next to the kerb or actually on the pavement. When there is no cycle lane I feel very exposed even when I am wearing a high-vis vest, helmet and lights. Motorists can be aggressive towards cyclists which forces us further towards the pavement. I have noticed that even when I am able to use a cycle lane the other road users tend to come much closer than I would say is safe. Worse still, people park over cycle lanes and are either not aware of, or don't care about the danger this causes.
Charlotte, Leeds, W Yorks, UK
One of the worst situations I find as a cyclist is being caught up in the traffic light Grand Prix. As soon as the lights change and it's "GO, GO, GO!...", woe betide any cyclist who's off to a wobbly start. With modern lights often incorporating pedestrian priorities, I would have thought it possible to provide a little extra for "cyclists" in the form of a small green light that comes on for say 5 seconds before all the budding drag racers hit their nitro' buttons when the main lights change.
Richard, Sutton Coldfield
Today I am suffering from a painfully strained shoulder as a result of a cycling incident. But guess what - it was another cyclist who caused the crash. I was cycling up a hill on the left-hand side of a generously wide residential street when a cyclist wearing all the gear shot out just in front of me between two parked cars - he had clearly been bombing down the pavement on the wrong side - and crashed straight into my front wheel, jarring my bike and me quite severely. Hm....
I think it's simply a matter of women failing to appreciate the space needed by HGVs when manoeuvring as well as men. Tests have shown that differences in spatial awareness account for why men are generally better than women at parking, and this could be an extension of the same problem. Men are also more likely to be familiar with HGVs and their characteristics than women. This isn't to say that there aren't some excellent exceptions to the rule!
Jamie, Wendover, UK
Having seen the way cyclists ride in London, I'm not surprised many are involved in accidents. They ride without lights after dark, ignore traffic lights and ride aggressively as if they own the road. Apparently that is how the LCC want it in parts of London - pedestrians and cyclists only (and I'm sure they would prefer not to have pedestrians in their way as they cycle along the pavement).
"The main problem is the attitude of other drivers, she says, as they make her feel like she does not belong on the road" I cycle daily and I wholeheartedly agree with this comment. I do not allow my children to cycle to school because of this. Lorry drivers tend to be more polite than car or van drivers, but are more dangerous because of blind spots.
Al, T Wells, UK
This is a really interesting article. I think men and women generally do cycle differently for all the reasons mentioned. Riding too close to the kerb is a real issue, cars will try to squeeze past if they can even when there is oncoming traffic. By riding slightly further from the kerb (about a foot beyond the grids) you will generally force drives to cross the white line in order to overtake. This puts them in danger of being hit by oncoming traffic which focuses their mind on choosing carefully when they overtake. When my wife and I our out on our tandem we tend to get far more room from drivers; perhaps because the stoker (that's the one on the back) can easily make eye contact with the driver before they overtake?
In a perfect world it would be safest to overtake the lorry on the right hand side, but my experience of venturing nearer the middle of the road (no-man's land) makes me very wary as you're competing for space with motorcyclists doing the same. Also it puts you in a position where you're closer to the oncoming traffic, equally dangerous. Rock and a hard place really...
Stewart Paling, London