> As a pedestrian my number one danger are cyclists

Annual pedestrian deaths from collisions with motor vehicles in the US: a little under 5000.

Do you seriously believe 5000 pedestrians a year are being killed by bicycles? I would be surprised if there were as many as 500 pedestrian fatalities a year that had anything to do with bicycles.

Cyclists are not your number one danger. They are nowhere near to being your number one danger.

Please calculate the kinetic energy of a car of 1500kg at 30km/h vs a bike of 100kg at the same speed and reconsider your argument.

Kinetic energy doesn't kill cyclists in the usual circumstances.

You need very little kinetic energy to make a cyclist topple and fall. The fall itself can lead to injury and death, lying on a street in the midst of all the traffic is even more dangerous.

Any touching of car and cyclist is very, very dangerous. That's why I brought up the example of cyclists passing cars with practically no space between them. They feel it's safe, but it's incredibly dangerous.

Which "normal circumstances" are you referring to? Suggesting that a fall itself might kill a cyclist is pretty far fetched.

Lying on a street - yes. Because cars might roll over you, cause of the kinetic energy.

Getting squished between cars - yes. Because of the huge mass of the car.

Banging your head against an opening car door - yes. This time it is because of your own kinetic energy that hits a small surface area which is immobile cause of the mass of the car.

So it is quite dangerous to get near to cars, yes. But almost always because of the huge mass of the cars, especially if they are moving. That was the point of ggp.

Total kinetic enegy has little to do with it, a car can kill someone at 1MPH by running them over. At 30+MPH a cyclist can easily kill themselves by hitting something head first even with a helmet. Simple truth is only an idiot goes 30MPH in a bike lane where they can easily hit someone.

30+ mph! Thats tour de france velocity with a lot of kinetic energy (albeit still less than a car at 10mph I think).

Sprinting at 30mph expecally down a hill is vastly easer than mainting that for the long term.

Many of these people where not going all that fast. https://en.wikipedia.org/wiki/List_of_cyclists_with_a_cyclin...

Well, an 80 kg cyclist+bicycle system at 30mph has about 7 000 joules of kinetic energy.

A 1 ton car at 10 mph has 9 000 joules of kinetic energy, so about 30% more.

My point was that the car's mass at the point of impact doesn't matter, because the cyclist doesn't die of an immediate trauma from the collision. He could be tipped over by a pedestrian, or bad street conditions.

He dies – as you put correctly – because of all the cars around him. Of course kinetic energy is relevant there, but it doesn't matter to the argument, because the claim was that being touched by a car is much more dangerous than being touched by a cyclist. And that's wrong.

As soon as the cyclist falls he's in mortal danger.

> A cyclist that passes a slow car with, say, 30 km/h

No casual cyclist can sustain 30kph on a level road. My average speed when I was in top shape and biking 20km every day was 15kph. I don't think you understand just how fucking terrifying 30kph is when you're on a bicycle. I don't want to ride at that speed, it's really way faster than I can react, and I feel it very well. When you're in a car, 50kph feels like nothing at all, but on a bicycle you're acutely aware how you're propelling your body sitting on a few thin tubes of metal and two flimsy wheels at a speed at which you have no control over. I've reached 50kph only once in my life on a downhill stretch of good asphalt road on a Sunday with no traffic as far as the eye could see and I don't ever want to do it again. 30kph is scary. 50kph is terrifying.

plus cars heavily respect red lights, something most cyclists don't give a fraction of a f__k about.

And on top of that - their brakes are useless, they in many cases drive as fast as they can, downhill or not. Yeah, for me as a driver, cyclists are the biggest threat in the cities and outside (effectively anywhere but highways). As a pedestrian, cyclists are again the biggest thread in the towns mostly on pedestrian crossings.

On an average day walking about London, I will probably see 5 cars an hour jump a blatant red and 10-15 accelerate on yellow to beat the red. And that's ignoring all the other dangerous things that cars do.

Cyclists have a tendency to disregard traffic lights (and I feel that urge myself when cycling), because it's so darn strenuous to get back to normal speed.

As a pedestrian stopping and going again is effortless. As a car driver the same. Only cyclists dread stopping.

Stopping and starting a car may not require physical effort but it does burn more fuel, gives you a less even ride, and makes traffic flow less smoothly. When I'm driving I try quite hard to avoid having to stop at lights. (By slowing gradually as I approach them, not by going through them when red.) I warmly commend this policy to other drivers.

A cyclist is not passing slow/stopped cars with inches to spare at 30km/h.

Is it really important if it is 20 or 30 km/h? Is 20 km/h or 10 km/h not dangerous?

I have experienced the former.

Yes there are crazy cyclists out there. Once a year I meet one.

Do you know how many careless car drivers I meet? At least one each time I bike more than 3km. Not crazy (those I find every 100km), just careless. But thats enough to threaten my life.

Either way, the cyclist is on the receiving end of the risk (we're not talking about bike vs pedestrians here). So no Symmetry. Mass matters. A lot.

> Is it really important if it is 20 or 30 km/h? Is 20 km/h or 10 km/h not dangerous?

Yes, it is. At 10km/h it's really not dangerous; at 30km/h an open door may kill the cyclist, and a hitting pedestrian may be severely hurt them. Speed is that a relevant factor.