Why this British crossroads was so dangerous
Why Hacker News recommends it
Used as the go-to visual demonstration of A-pillar blind spots and badly designed junctions.
What it is
Tom Scott explains why Ipley Cross in England's New Forest was one of Britain's most dangerous junctions. The angled crossroads lets a car's A-pillar hide approaching traffic and cyclists because there is no relative motion in the driver's view.
Recommended by 3 HN commenters across 3 different months, 2020 to 2025.
What Hacker News said
Recommends sitharus · 2020-04 · on “Collision Course: a type of road junction that is dangerous for cyclists (2018)”
The Tom Scott video has a good animation on this: [this video] Because of the layout of the junction the cars are actually approaching from behind the cyclists.
Recommends zinekeller · 2022-02 · on “Tesla to recall vehicles that may disobey stop signs”
The Wired reporting is based on Bez's article on Singletrack (as stated): [LINK] Tom Scott made a good complementary video about this: [this video] It's already fixed just last month: [LINK] and [LINK]
Recommends DoughnutHole · 2022-08 · on “Effects of large vehicles on pedestrian and pedal-cyclist injury severity”
Tom Scott has a good video for anyone looking for a visual of this phenomenon: [this video] He shows off a rural (and thankfully now fixed) crossroads in the UK with seemingly great visibility and an unusually high rate of cyclist fatalities - the roads are at such an angle that any reckless driving speed can align with a reasonable cycling speed such that the driver's door pillar can block visibility of a cyclist with right of way right up to the point of impact - and it's compounded by the fact that the car is necessarily approaching from behind the cyclist, so a passing cyclist will be unaware of the danger possibly until they get hit. Of course if drivers in the area actually followed the sto
Cites whymauri · 2021-12 · on “In 2019 40% of San Francisco traffic fatalities are from left turns”
For a particularly dramatic example of this, Tom Scott made a video about an intersection in the UK that's poorly designed for visibility: [this video]
Cites matsemann · 2021-12 · on “In 2019 40% of San Francisco traffic fatalities are from left turns”
Sounds to me like cars shouldn't be allowed to drive where pedestrians travel, if they can't really avoid driving people over. Edit: This Tom Scott video shows how a cyclist can be perfectly occluded by the A-pillar while both are moving [this video]
Cites kibwen · 2021-12 · on “In 2019 40% of San Francisco traffic fatalities are from left turns”
> The angles we were converging at meant that he basically disappeared into the background because there was no relative motion. This effect is demonstrated in this video about a particularly dangerous crossing in the UK: [this video]
Cites antiterra · 2022-03 · on “Blindspots on SUVs, vans, and pickups are bad for pedestrian health”
The blind spots in the article are from the A pillar, which isn’t addressed by rear view mirrors. The momentum would tend toward this being solved by sensors/computer vision, but maybe chip shortages have curtailed that. Tom Scott presented an interesting example of A pillar blind spots causing problems: [this video]
Cites notatoad · 2024-01 · on “California debuts 'turbo roundabout' to fix intersection near Bay Area”
this article seems to have some actual pictures: [LINK] the previous configuration as shown on the satellite image looks a lot like the intersection Tom Scott made a video about, where the intersecting road is angled to keep cross-traffic hidden behind a car's a-pillar. [this video]