3 HN users recommended this explainer3 months2020–2025score 3
Years with an HN recommendation, 2007–2026
Used as the go-to visual demonstration of A-pillar blind spots and badly designed junctions.
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.
“Tom Scott has a good video for anyone looking for a visual of this phenomenon” (HN, 2022)
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.
Good animation of cars approaching from behind cyclists.
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]
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 stop signs no one would get hit - but if you watch the video in a five minute period genuinely only about half of the cars passing through actually come to a complete stop at the stop sign. You need more than signage and quietly hoping that people to do the right thing.
Visual of a UK crossroads where the door pillar hides cyclists.
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]
A dramatic example of a junction poorly designed for visibility.
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]
Shows a cyclist perfectly occluded by the A-pillar.
> 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]
Demonstrates the no-relative-motion effect at a dangerous crossing.
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]
Interesting example of A-pillar blind spots causing problems.
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]
Similar angled intersection hiding cross-traffic behind the A-pillar.
See [this video] for an example. One of the advantages of raking the front windshield for aerodynamics is changing the geometry for the A pillar to be more sideways instead of vertical, allowing a bit more hope of seeing something.
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