[vhfpmr (OP)]

Referring to this page, there are 3782 cyclists at fault for failing to look properly, and 7565 non-cyclists. If we assume that there are 8 times as many non-cycling road users as cyclists, does it follow that:

1.   Cyclists are four times more likely to be at fault because they’re producing half as many incidents from 8 times fewer vehicles.
2.   Cyclists are 16 times less likely to be at fault because non-cyclists are still producing twice the incidents despite having 8 times fewer potential targets for careless road users to collide with.
3.   From the product of 1&2 above, cyclists are four times less likely to be at fault overall.
4.   Cyclists are just half as likely to be at fault, because those who haven’t crashed are not relevant.
5.   None of the above.

Personally, I’m inclined to think it’s (3), because the probability of an accident must be the probability of finding a careless road user multiplied by the probability of them finding something to hit.

[alancalverd]

If we assume that there are 8 times as many non-cycling road users as cyclists

There's something fishy about the statistics. Chart 1 says that pedal cyclists travelled 200,000,000,000 miles in the UK in 2020. That equals the distance covered by all the cars in the UK during the same period. Does every cyclist really pedal 8 times further than every car driver?
Really?

[paul cotter]

I see that study is uk based. In Ireland cyclists are immune to traffic lights, stop signs and any traffic control one can think of. As you may gather this is a pet grievance of mine. Apologies for off-topic rant, I just couldn't help it!

[alancalverd]

Sounds like Cambridge. Or London.

[vhfpmr (OP)]

If we assume that there are 8 times as many non-cycling road users as cyclists

There's something fishy about the statistics. Chart 1 says that pedal cyclists travelled 200,000,000,000 miles in the UK in 2020. That equals the distance covered by all the cars in the UK during the same period. Does every cyclist really pedal 8 times further than every car driver?
Really?

No it doesn't, it says there are 5.03 billion vehicle miles cycled in 2020, which is 1.8% of the 280.5 BVM for motor traffic.
https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/1028165/road-traffic-estimates-in-great-britain-2020.pdf

I see that study is uk based. In Ireland cyclists are immune to traffic lights, stop signs and any traffic control one can think of. As you may gather this is a pet grievance of mine. Apologies for off-topic rant, I just couldn't help it!

I did consider generalising the question so that it wouldn't descend into an anti-cycling rant, but I assumed it ought not to be necessary on a science forum.

Red Light Car Bike.JPG (284.43 kB . 1449x533 - viewed 1961 times)

[alancalverd]

No it doesn't, it says there are 5.03 billion vehicle miles cycled in 2020, which is 1.8% of the 280.5 BVM for motor traffic.

Aha! I see what has happened here - somewhat inexplicit graph legend.

So the number of cyclists killed per billion miles cycled, almost doubled during lockdown, when traffic density was lowest.