If you're driving a long and a bike pulls out suddenly in front of you, unless you have the attitude of "fuck it, just run them over" then yes, a bike can still be a massive threat to a car.

No, it can't. Not in any physical sense. If a car swerves and hits a cyclist at 30kph, the cyclist is almost certain to be injured, if not dead. If a bike swerves and hits a car, they might scratch the paint. When will the false equivalences end?

Actually, it absolutely can, in the same way that striking a deer in a car can kill the motorists. Horrifying, but true and dangerous.

Not to mention the fact that a cyclist at full speed can absolutely kill a person, especially a small person.

Any motorist driving irresponsibly should be ticketed and any cyclists doing the same should also be ticketed.

Similarly, a deer (which weighs less than a human on a bike and probably has a lower center of gravity) could never be a threat to a car. Running into a deer couldn't do more than scratch the paint on a car. I've never heard of a single person ever getting killed when they drove into a deer. /sarcasm

Bikes can certainly damage cars. I had a friend who went through a passenger window (breaking through the glass) of a car that pulled out in front of him. If that was the driver's side window, there is a nonzero chance that the driver might have been knocked out or somehow wrecked his car.

Also, cars (and their drivers) can definitely get hurt trying to avoid collisions with bikers by swerving out of the way and colliding with other vehicles/buildings/going off the road into a ditch.

The several grandfather post to this would have said essentially the same thing and would be much less controversial if it just read "a bike is less of a threat to a car than a car is to a bike", rather than using the absolutes of "always" and "never" (which rarely can be used to describe real life situations).

Also, despite historical claims, I'm fairly confident that most roads (by any reasonable definition of most) in the US today were built with the majority of design thought about drivers.

If a car swerves to avoid a cyclist and hits another car...

Then the car serves as the immediately threat to the other car, no the cyclist. This why you are supposed to drive defensively when operating a motor vehicle, so sudden changes in a situation doesn't cause you to crash into someone or something.

When you're behind the wheel of a car, yes. When you're around a car, no.

Even if someone's driving defensively, sudden changes in the environment lead to a more dangerous situation. If they're driving defensively, hopefully they can deal with it, but that is no reason to create dangerous situations in the first place.

...both car's passengers are surrounded by a metal cage that is trying to protect lives.

Are you being deliberately daft? Yes, the people in the cars are safer than a reckless person on a bicycle, but that doesn't mean the bicyclist isn't still putting them in some danger - those metal cages don't always succeed - as well as putting pedestrians and other bicyclists in more significant danger.

Okay, a reckless cyclist can put a driver in some danger, if the driver is going fast enough that the car can't be stopped quickly enough to avoid either hitting the cyclist or swerving into an oncoming lane.

However, in this constructed situation, it seems to me that the driver is being more unsafe by driving that fast.

So, you're in favor of lowering the speed limit to like 15 mph?

Yes: http://www.20splentyforus.org.uk/

If that's the parent's position, then I'm not sure I agree but I can't fault them for inconsistency. In an environment where many cars are traveling faster, though, it is nonetheless irresponsible and dangerous to others to ride a bike recklessly (or otherwise be unpredictable near fast-moving traffic).

I will agree that a relatively slow-moving bicycle on a road with fast-moving cars is indeed a dangerous situation for everyone. And I would agree that having similar speed vehicles together seems safer.

However, in places with vehicles going differing speeds, I would put the onus of safety on the faster vehicles.

What was being discussed was cyclists behaving recklessly. Imagine a cyclist blowing through a red light at the bottom of a hill, where they're going ~20ish. Cross traffic with a green light isn't necessarily going to see them until the last minute even if the cross traffic is moving at an otherwise safe speed. Pay attention in a city for a while, and you'll see things like this, and it rightly pisses off both drivers and us other cyclists.

I thought we were talking about whether or not bikes can be a massive threat to cars.

I have been paying attention in a city for a while. I have seen the situation you describe, but it's rare in my experience, even with SF supposedly full of reckless fixie-riders. Dangerous driving is far more common in my experience.

Hmm, yeah, scrolling up, there was more than a little hyperbole on both sides at the root of this thread. I agree a bike is not a "a massive threat to a car"; this doesn't mean it's okay for people to ride recklessly, or that they're not endangering others when they do.

And dangerous driving is probably more common (certainly by number of instances), and it should be condemned as well.

I certainly agree with all of that.

Stop being obtuse.

I wonder if someone could find stats on how many car-on-car collisions are caused by avoiding a bicycle, and compare that to how many car-on-bicycle collisions are caused by a swerving bicyclist (or any cause, really).

And then look at the resulting injuries.

No one is disputing that a reckless bicyclist is a danger to themselves. The question is how much of a danger they are to others, because more people feel more okay intervening when someone is presenting a danger to others.

Also a pedestrian, or a jogger, might pull out suddenly in front of you. But this is no ground to make transport by foot a privilege.

I'm a cyclist who has never sat behind the wheel of a car (well I'm lazy now so more of a taxi-ist, but a cyclist at heart) and completely agree with you. But that doesn't change the fact that yes, while cars may be far more dangerous to bikes than the other way around, a bike still can be very dangerous to a car.

By that logic, pedestrians should be able to walk in the middle of roads, since they're not a threat to a car.

They can, at least in California: as a pedestrian, you're entitled to cross the road at any intersection (crosswalk lights must be followed, but in their absence you're free to cross at any time). By law, all drivers must come to a complete stop until you have reached the curb.

I don't mean crossing the road. I mean traveling with traffic in a lane.

You will need to explain how the fact that pedestrians are even less threatening and more vulnerable is the same as implying this gives them the right to walk on the middle of the road.

I suspect that pedestrians are less threatening because they rarely walk in traffic (both because it's illegal, and because it's obviously dangerous). But for bicyclists, it's legal, and apparently the danger isn't enough to stop a lot of people.

The way you describe it, my impression is that the real problem is that you are not considering bikes as participants of traffic, but obstacles in the way of your car.

I'm not considering automobiles as inherently more "valid" participants of traffic than bicycles. I just consider any road where two types of vehicles of very different sizes which behave very differently to be an inherently unsafe and inefficient road for all participants. Obviously, the occupants of the larger vehicles are much safer in collisions with the smaller vehicles, but that's not my primary consideration. I just think the roads, or at the very least the lanes, should be dedicated to only bikes or only automobiles. Since there are far more automobiles than bicycles on most roads, if building new infrastructure is out of the question, I think it makes sense to not allow bikes to share the lanes. This isn't a condemnation of bicycle commuting, but rather a basic appeal to safety and organization, just like pedestrians are not allowed to share lanes with automobiles. The current situation on most roads, where a small number of small slow-moving bikes occupy lanes in the middle of a sea of automobiles, is just a disaster waiting to happen (and in big cities, it happens all the time).

I'm not considering big rig trucks as inherently more "valid" participants of traffic than passenger cars. I just consider any road where two types of vehicles of very different sizes which behave very differently to be an inherently unsafe and inefficient road for all participants. Obviously, the occupants of the larger vehicles are much safer in collisions with the smaller vehicles, but that's not my primary consideration...

Tractor trailers do not behave very differently than normal automobiles on freeways, and they're generally not allowed on smaller roads.

Ok, since I can't edit the comment any more: my whole point was that the threats are not equivalent, and describing the situation as "car vs bike" as if they are on equal terms is wrong.

Instead people are getting all anal about the use of "never" and "always", and use far-fetched examples where a car can be threatened by a bike when atttempting to avoid running over it and crashing into something else.

Way to direct the discussion away from the point I'm trying to make. Look at this Dutch national report on bike safety:

http://www.swov.nl/rapport/Ss_RA/RA47.pdf

The Netherlands has one of the highest percentage of people riding bikes with an estimated 14 million bicycles for 16.5 million inhabitants. It has one of the most developed infrastructures in favour of bike safety, about the safest traffic in Europe in general, and as a culture it is about as bike-oriented as it gets. Despite all of this, travelling with your bike is still 4.7 times more dangerous than travelling with a car.

I am in no way trying to absolve cyclists or pedestrians of their responsibility in traffic safety, but denying that they aren't inherently more vulnerable and that infrastructure design should emphasize their safety is absurd.

That 4.7x can probably be completely attributed to all the safety equipment that protects the person in a car. A more valid metric would be accidents (not injuries) per vehicle mile traveled.

No, it wouldn't, because that's not what we're discussing. The discussion was danger one vehicle poses to the other, and the only significant cause for bike fatalities is car accidents - there are no chasms to fall in in the flattest country in the world, and the speed at which one travels on a bike is much slower so much less likely to be fatal in case of a crash with a stationary object. So this is a very real metric of how dangerous bikes are to cars and vice versa.

EDIT: And even then it's skewed in favour of the car, because for cars the fatality rate is more likely due to crashes with other cars.

Bikes are threats to pedestrians. I've never hit a pedestrian on a bike but I've come close. I've also been hit by a car while on a bike (at a low speed, enough to trash the bike but I was able to hop off in time) so I have sympathy here.

Bikes injure pedestrians fairly often. My understanding is they rarely kill (though I'm happy to defer on either to someone bringing actual statistics to the table).

They don't, you need higher speeds for that (freak accidents don't count). Source: the lack of bicycle-caused deaths in the Netherlands.

Well, apparently they do occasionally (though you'd probably be correct in labeling it a "freak accident"):

http://www.sfexaminer.com/sanfrancisco/no-jail-for-cyclist-c...