How do cyclists die in cities?

[TheInternet]

There has been a lot discussion about the number of fatalities on city roads and what can be done to reduce the risks, but I have not seen much detail about the type of accidents that occur and the injuries which result. The most publicised incidents involve HGVs turning across cyclists, which is an obvious problem to understand and clear consequences, however the circumstances leading to other accidents are not so apparent to me, nor the outcomes.

Is it the case that most deaths are due to crush injuries? If not then presumably collision is the next option, despite impact speeds being around 30mph max. Or is it a combination, such as an initial impact leading to being crushed by a second vehicle?

If anyone knows of any available stats/documents on the matter it'd be interesting to see.

[Vladimir]

I used to cycle a lot in Bristol and never died.
I did crash a lot at Ashton Court though.

[okgo]

Most of the deaths are because people's bodies get crushed to fk by wheels. I understand one of the London deaths was because the truck ran over her head...

Massive internal injury is likely cause of actual death in most cases.

[Ray Luxury-Yacht]

TheInternet said:

There has been a lot discussion about the number of fatalities on city roads and what can be done to reduce the risks, but I have not seen much detail about the type of accidents that occur and the injuries which result. The most publicised incidents involve HGVs turning across cyclists, which is an obvious problem to understand and clear consequences, however the circumstances leading to other accidents are not so apparent to me, nor the outcomes.

Is it the case that most deaths are due to crush injuries? If not then presumably collision is the next option, despite impact speeds being around 30mph max. Or is it a combination, such as an initial impact leading to being crushed by a second vehicle?

If anyone knows of any available stats/documents on the matter it'd be interesting to see.

Not sure, why not ask the internet?

Oh, you already have!

[Disco You]

Crush injuries followed by brain and spinal chord injuries I'd have thought...

[Gizmoish]

Disco You said:

Crush injuries followed by brain and spinal chord injuries I'd have thought...

Yep. Most are chest/thoracic crush which renders the helmet debate irrelevant, too.

Might point out though, that impact at "only" 30mph is quite... something.

[okgo]

Hitting something stationary at 30mph on a bike is usually game over, many time trial riders have hit the back of stuff that has stopped because they were looking down instant death in many cases.

[TheInternet]

Disco You said:

Crush injuries followed by brain and spinal chord injuries I'd have thought...

What brains etc.

So the league table might be:
1. Crushed (blood loss, head injuries)
2. Collided (head injuries, no blood loss)
3. Cut (loss of blood, no head injuries)
4. Old age / natural causes

Considering these, is there generally only one vehicle involved or there often a secondary incident that is ultimately responsible i.e. a minor interaction with one vehicle results in a major interaction with a second. For example hitting car door leads to crushing by bus.

It seems relatively trivial to prevent most serious 'primary' vehicle incidents, they are also the most obvious, whereas incidents involving a secondary vehicle are much less predictable and makes judging risk considerably more difficult.

[TheInternet]

Gizmoish said:

Might point out though, that impact at "only" 30mph is quite... something.

Fair point, merely suggesting that 30ish as a maximum must improve ones chances compared to 50+mph out of town.

[Gizmoish]

Preventing secondary impacts is almost impossible.

[TheInternet]

Gizmoish said:

Preventing secondary impacts is almost impossible.

Indeed, but it would be useful to know what proportion of these incidents involved more than one motor vehicle.

[Getragdogleg]

I had this crazy idea that an animal (in this case us) can only withstand an impact at the top speed it can run at. Anything above that would cause damage that the faster the speed the less likely it would be to survive.

[grumbledoak]

I don't think speed is an issue in London. The big vehicles can kill you at walking pace.

[grumbledoak]

And not just going over you with the wheels, either - a bus windscreen at walking pace, total momentum transfer straight to your brain with no crumple zones at all. Jam.

[TheInternet]

anonymous said:

[redacted]

Do you know where accident details are available? I doubt there is any central record describing their nature in ways I'd like. As you say, it is very complex, but seemed worth trying to establish whether it's as dangerous to pass stationary traffic down the middle of the road as it is to pass a lorry on the left. I expect several would be fine with the former but not the latter, yet could potentially pose similar risks.

[iPlod999]

Anyone that rides a bike should see this.


https://www.youtube.com/watch?v=wzL0Kyk4m-8&fe... from Samsung Mobile

[TheInternet]

grumbledoak said:

And not just going over you with the wheels, either - a bus windscreen at walking pace, total momentum transfer straight to your brain with no crumple zones at all. Jam.

You mean cycling into a bus at ~20mph? Merely walking into a bus is not going to do you much harm (unless followed by the mincemeat phase).

[grumbledoak]

No. The bus into you at walking pace. Conservation of momentum.

[TheInternet]

iPlod999 said:

Anyone that rides a bike should see this.
https://www.youtube.com/watch?v=wzL0Kyk4m-8&fe... from Samsung Mobile

As mentioned at the outset I think most are aware of the dangers large vehicles pose (as noted by the countless warning stickers adorning the back of many), almost nothing is said about how other KSI incidents arise.

[TheInternet]

grumbledoak said:

No. The bus into you at walking pace. Conservation of momentum.

A 4mph bus slamming into someone is not going to 'jam' them.