Careless cyclists.

P_1

Tigger wrote: »

Most literature for example here http://www.drivingschoolireland.com/speed.html

Suggest a thinking distance of 4.5-5.5m and total stopping distance of 10-11m for a car
So how on earth can a cyclist stop in 6 m
Are they reacting faster ?

Good old F=MA

So a bike + the rider would have a mass of 100kg
Lets say the car has a mass of 2000kg

Given that there is much less mass to stop and both are travelling at the same speed it makes sense that the object with the less mass would take less time, distance and force to bring to a stop.

machiavellianme

Tigger wrote: »

Most literature for example here http://www.drivingschoolireland.com/speed.html

Suggest a thinking distance of 4.5-5.5m and total stopping distance of 10-11m for a car
So how on earth can a cyclist stop in 6 m
Are they reacting faster ?

Most literature quotes the theoretical limits of how quickly a car can stop but is rarely observed in practice.
If you want to bring reaction times into it...
Both will have similar reaction times, you'd imagine. The difference being that a cyclist at 30 km/h is already pushing their body to achieve that speed whereas the driver is not. Therefore, the cyclist will naturally stop applying forward momentum faster.
The next factor is wind resistance. Modern cars are aerodynamic by design to minimise external forces whereas every cyclist knows that the wind is always against you.


Last, but not least, due to the top heavy cycling position, the cyclist's centre of gravity tends towards a naturally unstable position. Sudden braking enhances this and most cyclists will come off, thereby rapidly shortening braking distances.

Also, don't forget there's at least another meter of engine in front of the driver to be counted whereas there's only half a wheel in front of the cyclist.

But even more crucially, even if both car and cyclist had the same stopping distance, I'd say most pedestrians would prefer to be hit by a 70kg cyclist than a 1570kg car doing the same speed.

Seth Brundle

machiavellianme wrote: »

Cars typically have 2 brakes (front or rear). This controls the deceleration and it is the contact of these 2 wheels with the road and the drums with the wheels which produces the friction necessary to stop. Bicycles have both front and rear brakes so all wheels are working towards deceleration, with more friction than just one set of wheels on the car.

erm, cars have a set of brakes on each wheel i.e. 4 and pretty much always did!

eeguy

kbannon wrote: »

erm, cars have a set of brakes on each wheel i.e. 4 and pretty much always did!

Typical boards answer. You give 10 good reasons completely disproving someone's point, they ignore 9 and nitpick 1.

bigar

LeoB wrote: »

Twice in the last week I have seen cyclists nearly causing accidents

A lot of people use this "nearly" (or "almost") this or that they saw cyclists do something they do not like or comprehend.

The view when you are on a bicycle is completely different from being in a car or standing on a footpath and likely the situation was not that dangerous at all.

AndrewJRenko

Ewan Hoosarmi wrote: »

Time for speed limits for cyclists perhaps?

Maybe a higher priority would be enforcing the existing speed limits for motorists, given that excess speed is one of the top three causes of the regular deaths on our roads?

Ewan Hoosarmi wrote: »

OK why should cyclists not be subject to speed restrictions? It was all fine when cyclists meant steel, sit-up-and-beg machines, but now cycling speeds are much, much higher.

We're told that speed kills. Does that not apply to cyclists? Do safe stopping distances not apply either?

Literally no - speed by cyclists does not kill others on the road, certainly not in the last 15 years.

cbreeze wrote: »

Motorists have to pass a driving test and know the rules of the road. Should cyclists be (a) obliged to pass a road theory test; (b) have insurance; (c) be subject to penalty for infringement?

It's an interesting comparison. Morphine users have to get a prescription from a doctor and buy their medication at a pharmacy. Should paracetamol users have to get a prescription and buy their medication at a pharmacy too?

jaxxx wrote: »

Not sure how common this is elsewhere, but I'm seeing a lot of cyslists not obeying traffic lights quite frequently. Now I don't cycle myself, but I assume that cyslists still have to adhere to traffic lights the same as drivers too?

"same a drivers too"? :D:D:D:D Hilarious
88% of red light jumpers at the Luas red light camera were motorists, not cyclists;

http://kerrycyclingcampaign.org/but-all-drivers-break-the-lights/

Look around you at any junction in the city and see the one or two or on a bad day, three or four drivers that push through after the lights have gone red, ignoring the pedestrians waiting to cross. But hey, the cyclists....

soups05 wrote: »

as to the thread, we don't have a cyclist problem or a driver problem, we have an asshole problem. it does not matter what mode of transport they happen to use.

Actually, it does matter - the assholes driving cars, vans of 1 or 2 or 3 tonnes of metal travelling at 20-120 kmph tend to kill people when things go wrong, whereas the assholes on a 10kg bike doing 10-20 kmph tend not to kill people.

average_runner wrote: »

That's the wrong attitude. You can't allow one to break the law and not the other.
If your not going to obey the rules of the road then stay off them.

Presumably you never break the speed limit on the road, right? Never, right?
Because if you are one of the vast majority of motorists who does break the speed limit, it would huge hypocrisy for you to make the comment above.

magicbastarder

eeguy wrote: »

Typical boards answer. You give 10 good reasons completely disproving someone's point, they ignore 9 and nitpick 1.

To be fair, it was quite a howler (s)he was pointing out.

Seth Brundle

eeguy wrote: »

Typical boards answer. You give 10 good reasons completely disproving someone's point, they ignore 9 and nitpick 1.

If the most obvious point in the post is wide off the mark, can the rest of the post be believed?

Podge_irl

RobertFoster wrote: »

Cyclists are permitted to use the left lane for all roundabout exits according to the ROTR.

The ROTR are just a guideline, so I'm not sure on the specifics of the legislation.

I'll be honest, I didn't know that and I suspect most people don't.

I feel a lot more comfortable taking the "correct" lane on a roundabout rather than worrying about cars trying to leave the roundabout across me. You would want to be pretty clear with your signalling if doing that. Regardless of the legality of it anyway, I would always be pretty adamant that the best course of action is to take ownership of the road as if in a car.

beauf

machiavellianme wrote: »

Tigger wrote: »

Most literature for example here http://www.drivingschoolireland.com/speed.html

Suggest a thinking distance of 4.5-5.5m and total stopping distance of 10-11m for a car
So how on earth can a cyclist stop in 6 m
Are they reacting faster ?

Most literature quotes the theoretical limits of how quickly a car can stop but is rarely observed in practice.
If you want to bring reaction times into it...
Both will have similar reaction times, you'd imagine. The difference being that a cyclist at 30 km/h is already pushing their body to achieve that speed whereas the driver is not. Therefore, the cyclist will naturally stop applying forward momentum faster.
The next factor is wind resistance. Modern cars are aerodynamic by design to minimise external forces whereas every cyclist knows that the wind is always against you.
Cars typically have 2 brakes (front or rear). This controls the deceleration and it is the contact of these 2 wheels with the road and the drums with the wheels which produces the friction necessary to stop. Bicycles have both front and rear brakes so all wheels are working towards deceleration, with more friction than just one set of wheels on the car.

Last, but not least, due to the top heavy cycling position, the cyclist's centre of gravity tends towards a naturally unstable position. Sudden braking enhances this and most cyclists will come off, thereby rapidly shortening braking distances.

Also, don't forget there's at least another meter of engine in front of the driver to be counted whereas there's only half a wheel in front of the cyclist.

But even more crucially, even if both car and cyclist had the same stopping distance, I'd say most pedestrians would prefer to be hit by a 70kg cyclist than a 1570kg car doing the same speed.

A lot of that doesn't really apply in real world braking. Most braking effort is on the front wheels the rear does very little.

Fact is neither stops instantly. There is huge variation in braking. Even between the same vehicle and different users.

The more important issue is appropriate speed for the conditions.

machiavellianme

kbannon wrote: »

erm, cars have a set of brakes on each wheel i.e. 4 and pretty much always did!

Fair enough. It has been years since I drove and I only ever noticed 2 sets of plates on the front wheels. Is there a drum or something on the back?

That would change things alright. Heavier weight applied across all 4 tyres would likely have similar coefficients of friction to a bicycle then. Obviously the tyre width and rubber type factors in but distances would be more comparable (apart from the wind resistance and instability of the cyclist).

magicbastarder

drum brakes are old technology and you'll only ever see them on rear wheels on modern cars - and with that, many cars are discs all round.

machiavellianme

beauf wrote: »

A lot of that doesn't really apply in real world braking. Most braking effort is on the front wheels the rear does very little.

Fact is neither stops instantly. There is huge variation in braking. Even between the same vehicle and different users.

The more important issue is appropriate speed for the conditions.

On a bicycle, the effort on the rear is based on the cyclists position. Assuming they're sitting down, there'll be approximately 1/3rd of their weight applicable should both brakes be applied equally. Experienced cyclists will not fancy going over the crossbars and will apply greater pressure to the rear as a result. They can also side swipe to increase friction and lower stopping distances whereas cars cannot. Furthermore, their narrower profile decreases the chances of hitting a pedestrian.

Most cars have front engines and the drivers own weight is more forward. So I guess my previous point about only one set of brakes doing any work isn't as far off the mark as the rear brakes would add less than 1/9th of the braking power.

As a final thought, how many would immediately think of a terrorist threat if a cyclist mounted a busy footpath at 30km/h? If a car did likewise, there'd be pandemonium.

kirving

For a given speed, a car should stop faster than a bike in practice.

The cyclist has far more things that if not done perfectly, will limit their ability to brake quickly, the car driver just has to smash the pedal and let the EBA (electronic braking assist) worry about the rest.

Most cars in the past 10-15 years will take over the application of barking if the driver hits the pedal hard enough.

The cyclist has to worry about the limited contact patch of the front wheel so even a little stone will cause issues, balance, weight distribution (all your weight has to be as far back as possible which is difficult with a high saddle), cable stretch, rubber deformation, water on the rim (last 3 not on hydraulic discs of course), potholes, braking force from their hand while also holding their weight steady.

It's in no way as simple as F=ma, and is why motorcycles have had ABS for years, and Bosch have one for pedal cycles too.

Also, this is a discussion about careless cyclists. Whataboutery regarding car drivers breaking speed limits and Luas lights has no bearing on the thread title, and similar would have posters banned from the cycling forum.

For what it's worth, I see cyclists put themselves in stupid situations every day, where despite being legal manoeuvres, their lives are in the hands of a car driver.

You can whinge all you like about how car drivers should be more responsibile as they have the ability to do more damage, and maybe they should, but don't be surprised when the occasional driver screws up and you've put yourself in their path. I should also point out that I cycle a lot btw.

AndrewJRenko

Kevin Irving wrote: »

For what it's worth, I see cyclists put themselves in stupid situations every day, where despite being legal manoeuvres, their lives are in the hands of a car driver.

You can whinge all you like about how car drivers should be more responsibile as they have the ability to do more damage, and maybe they should, but don't be surprised when the occasional driver screws up and you've put yourself in their path. I should also point out that I cycle a lot btw.

It's not so much that car drivers have the ability to do more damage. It's that they DO do more damage - every week they kill 3 or 4 people on our roads and maim many more, whereas cyclists don't.

I suppose that's why most people who prefer evidence-based public policy would think that legislation and enforcement measures for motorists should take a way higher priority than measures considered for cyclists.

kirving

machiavellianme wrote: »

On a bicycle, the effort on the rear is based on the cyclists position.

And also on the weight shift due to deceleration.

machiavellianme wrote: »

Assuming they're sitting down, there'll be approximately 1/3rd of their weight applicable should both brakes be applied equally.

That's too simplistic, and is based on static forces rather dynamics. In reality, the fastest way to stop will result in the back wheel having 0 force pressing down. ie: brake so hard that you transfer all forward momentum into rotational about the front wheel by braking, and rely on gravity to prevent you from going over the handlebars.

Most cyclists don't get anywhere close to this however.

the_pen_turner

AndrewJRenko wrote: »

It's not so much that car drivers have the ability to do more damage. It's that they DO do more damage - every week they kill 3 or 4 people on our roads and maim many more, whereas cyclists don't.

I suppose that's why most people who prefer evidence-based public policy would think that legislation and enforcement measures for motorists should take a way higher priority than measures considered for cyclists.

how many accidents are caused by cyclists
how many injuries are caused by cyclists

how do these compare to other road users.

dont talk about facts when none of us know them all

kirving

AndrewJRenko wrote: »

It's not so much that car drivers have the ability to do more damage. It's that they DO do more damage - every week they kill 3 or 4 people on our roads and maim many more, whereas cyclists don't.

I suppose that's why most people who prefer evidence-based public policy would think that legislation and enforcement measures for motorists should take a way higher priority than measures considered for cyclists.

You can enforce more rules on motorists, sure, but at the same time cyclists need to take responsibility for their own safety and not leave it to the driver.

Weepsie

Kevin Irving wrote: »

You can enforce more rules on motorists, sure, but at the same time cyclists need to take responsibility for their own safety and not leave it to the driver.

Precisely why many cyclists go in groups, 2 abreast, and take the main road position in the lane. That's taking responsibility and increasing safety. It's these things however which for some silly reason p!ss off people, and sees them skim past by elbow far too often.

Furthermore, I can't control what a driver is going to do (nor other cyclists) I've done all the correct, and legal things in the past and still been hit by a careless driver who was wholly impatient and wreckless.

There's one accident where I was careless (looking at the truck behind me), and admitted so, but it was also a situation in which the driver was on the phone, illegally in the lane and they saw me and decided beeping rather than moving was the solution.

kirving

Weepsie wrote: »

Precisely why many cyclists go in groups, 2 abreast, and take the main road position in the lane. That's taking responsibility and increasing safety. It's these things however which for some silly reason p!ss off people, and sees them skim past by elbow far too often.

I never said I had issue with the above, where did you get that idea from? That's responsible, safe and devensive cycling which is to be commended.

AndrewJRenko

the_pen_turner wrote: »

how many accidents are caused by cyclists
how many injuries are caused by cyclists

how do these compare to other road users.

dont talk about facts when none of us know them all

Have you worked out the reason why none of us know the facts about crashes (not accidents) and injuries caused by cyclists? It's because they are so insignificant that they never become a reporting category on their own.

The best thing that cyclists can do to take responsibility for the own safety is to clearly identify the cause of danger - the drivers who kill and maim on the road every day.

kirving

AndrewJRenko wrote: »

Have you worked out the reason why none of us know the facts about crashes (not accidents) and injuries caused by cyclists? It's because they are so insignificant that they never become a reporting category on their own.

Cyclists who cycle up the inside of a truck are absolutely partially responsible when it comes to getting killed. Legal or not, there is absolutely no justifiable reason why you should do that, and put your life in the hands of a truck driver. Yet I see it every single day.

AndrewJRenko wrote: »

The best thing that cyclists can do to take responsibility for the own safety is to clearly identify the cause of danger - the drivers who kill and maim on the road every day.

That's a very holistic view of road safety in general there, and perpetuates an 'us and them' mentality which helps absolutely noone.

the_pen_turner

AndrewJRenko wrote: »

Have you worked out the reason why none of us know the facts about crashes (not accidents) and injuries caused by cyclists? It's because they are so insignificant that they never become a reporting category on their own.

The best thing that cyclists can do to take responsibility for the own safety is to clearly identify the cause of danger - the drivers who kill and maim on the road every day.

the reason there ais no data on that is that they wont look at crashes with an unbiased view. they look at the blaming th emotorist before any eveidence is seen.

ov all the pedestrians and cyclists that died in the last few years , how many have been fully or partially their own fault. its a lot more than is reported in the news.
if you look at dash cam videos on you tube it shows a lot of crashes caused by pedestrians and cyclists. i dont see why that wouldnt apply across the board and happen reguarly.
iv seen some shocking stuff from cylists and pedestrians that could have very easily killed them or caused a crash between other cars

dashcamdanny

No problem with cycles other than the fact not many of them look over their shoulders when pulling out to over take another cycle. Which I put down to a lack of training available. One of the first basic rules of a motorcycle test is a life saver glance. The same apply s to every road user.

People hate them because the get held up, but if you consider that every cycle in Dublin is potentially replacing a car. drivers are probably getting there faster.

Wishbone Ash

Kevin Irving wrote: »

... but at the same time cyclists need to take responsibility for their own safety and not leave it to the driver.

I take responsibility for my own safety as much as I can and cycle in a legal manner but how can I prevent drivers from passing way too close or for leaning on the horn or shouting abuse at me when I'm doing nothing wrong.

Common examples:

1. I'm cycling around on a bend with a continuous white line. Driver decides to illegally overtake and meets another vehicle which causes them to swerve in to me to avoid a collision with the other vehicle.

2. I wish to take the third exit at a roundabout and safely move over to the right lane and enter the roundabout with my right arm extended. For some reason this seems to piss off some motorists who seem to think cyclists should not be on a roundabout at all and drivers will lean on the horn as they attempt a close pass on the left side.

3. I'm cycling along a bus lane when a bus driver/taxi driver decides to perform a close 'punishment pass' because in their ignorance they assume I'm doing something illegal.

I'd be interested to know how you would propose that I prevent these illegal actions from motorists bearing in mind that I am acting responsibly and legally.

Wishbone Ash

the_pen_turner wrote: »

..if you look at dash cam videos on you tube it shows a lot of crashes caused by pedestrians and cyclists...

Have a look at the footage put up from cycle cameras and you'll see the complete opposite - lots of shocking footage of dangerous driving from motorists.

Wishbone Ash

dashcamdanny wrote: »

...People hate them because the get held up....

LOL - earlier on in this thread, we were going too fast! :rolleyes:

OldMrBrennan83

This post has been deleted.

uck51js9zml2yt

Wishbone Ash wrote: »

Some cyclists.

Have cyclists been killing pedestrians lately?

Actually yes!

Well cyclist was killed hitting a pedestrian who ventured into the cycle path in the phoenix park and a pedestrian seriously injured on Gardiner st.

dashcamdanny

Wishbone Ash wrote: »

LOL - earlier on in this thread, we were going too fast! :rolleyes:

Motorist in general. Which is obvious if you follow any motoring forums.
Not me by the way. Im fairly pro cycle as its part of the congestion solution. ..

I dont care how fast they go. It will NOT hurt me in the slightest behind a steel door.