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A Type of Road Junction that Kills Cyclists

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Re: A Type of Road Junction that Kills Cyclists

#51

Post by bo1024 »

matte_black wrote: post #4

Wow, after all these years I finally learned the name of this phenomenon, constant bearing decreasing range. I recall a scene in the movie Sin City where two cars crash and the camera was moving in CBDR to the perpendicular car as it zoomed into the impact site. I thought it was a cool shot. Also I’ve almost hit pedestrians several times when they were obscured by my A pillar. Sometimes I wonder if I would have actua…

As one such pedestrian, this near-miss happens all the time, although half the time it's because drivers aren't even trying to look (e.g. a driver turning right will only be looking to their left while rolling through a stop).

So I find A-pillar design very aggravating -- though not as aggravating as drivers who roll up to and through stop signs at a constant speed approximately equal to my running speed.

Re: A Type of Road Junction that Kills Cyclists

#52

Post by metaphor »

matte_black wrote: post #31
metaphor wrote: post #21

Earlier quoted context omitted.

To be sure, there's a nice and bold sub-section of the article titled A Simple Solution which I (perhaps naively) presumed the parent was referring to--further reinforced (in my mind) by a username which subtly suggested specialization in traffic engineering.

It would seem odd to be disappointed with a solution that wasn’t actually implemented.

To the contrary, I often experience such disappoints during design reviews in my day job.

I think we both can agree that the discussion has clearly digressed into unconstructive pedantry territory.

Re: A Type of Road Junction that Kills Cyclists

#53

Post by kevin_thibedeau »

bdamm wrote: post #17
temp-dude-87844 wrote: post #8

There's a lot of math in this article about blind spots and car pillars and whatnot, but a Google Maps Street View appears to show the terrain and brush blocking the view on approach [1][2], making all of this math largely moot. That the drivers in question didn't even so much as slow down for this approach is beyond reckless, aside from the other lawbreaking that followed. The 'Give Way' sign is idiotic, put a Stop…

Indeed, a stop sign would solve this, wouldn’t it? Simplist & cheapest solution first. The point about the geometry is that it doesn’t matter at which point the driver can see over the hill and brush; they still won’t see the cyclist.

There are stop signs now (as of June 2017) and STOP markings in the road. Streetview shows old imagery from 2015 when viewed from the offending road but Beaulieu Rd. is newer.

Re: A Type of Road Junction that Kills Cyclists

#54

Post by swimfar »

u801e wrote: post #36
protomyth wrote: post #29

Earlier quoted context omitted.

In the US, they would put up a stop sign and park a cop near there for some instant, costly learning experiences. Although, if the speed is sufficient you would probably get an overpass, particularly if one road is a known truck route. It would be interesting to build a bicycle only overpass.

The US also tends to overuse stop signs when a yield (give way) sign would suffice. That is, if there is sufficient visibility of approaching traffic, coming to a complete stop is not necessary to safely yield to any conflicting traffic. Also, coming to a complete stop and then proceeding isn't sufficient to properly yield to approaching traffic. In the end, stop signs end up being treated like yield signs. The only…

In the end, stop signs end up being treated like yield signs.

This definitely varies based on where in the US you are. In California almost no one comes to a complete stop. (That's probably why rolling through a stop sign is called a "California Roll"). But in many other parts of the country people do, even if there are no cars around.

Re: A Type of Road Junction that Kills Cyclists

#55

Post by jessaustin »

csours wrote: post #22

Unrelated, a few days ago I was thinking about this intersection: https://www.google.com/maps/@31.5075019,-96.3308952,243m/dat... Traffic on Hwy 164 does not stop, Hwy 39 does stop. However Hwy 39 has yield lanes that can be used to enter 164 via a right turn, and only slowing down, and not coming to a complete stop. A few years ago there was a lot of gas drilling in the area, and the trucks working the drilling site…

A few years ago there was a lot of gas drilling in the area...

Haha I zoomed the map view out a bit: you're not kidding! That's a lot of drill sites!

Re: A Type of Road Junction that Kills Cyclists

#56

Post by anonymfus »

azernik wrote: post #39
djsumdog wrote: post #33

I know most comments indicate that even without the maths, the rolling geography would seem to block the view, and that the best solution would be a 4-way stop, a roundabout or the split road suggestion in the article. But going back to the a-pillar, Volvo did have a concept design with a see through a-pillar. I'm not sure why it never made it to market. I'm guessing it didn't pass their safety requirements? http://w…

Judging from the considerations evinced in this article, pillar strength and thus rollover safety do seem to be limiting factors: https://www.redbook.com.au/car-news/toyota/toyota-patents-tr... It also indicates, however, that the industry is putting real development effort into solving the problem, whether through clever optics like Toyota's efforts, or cameras and screens like Jaguar's concept.

May be it would be possible to improve rollover safety by putting additional pillars inside the car, for example between chair backs?

Re: A Type of Road Junction that Kills Cyclists

#57

Post by cmurf »

u801e wrote: post #36
protomyth wrote: post #29

Earlier quoted context omitted.

In the US, they would put up a stop sign and park a cop near there for some instant, costly learning experiences. Although, if the speed is sufficient you would probably get an overpass, particularly if one road is a known truck route. It would be interesting to build a bicycle only overpass.

The US also tends to overuse stop signs when a yield (give way) sign would suffice. That is, if there is sufficient visibility of approaching traffic, coming to a complete stop is not necessary to safely yield to any conflicting traffic. Also, coming to a complete stop and then proceeding isn't sufficient to properly yield to approaching traffic. In the end, stop signs end up being treated like yield signs. The only…

Americans don't do yield signs very well except in the most obvious situations that shouldn't even need yield signs, like highway on ramps, and intersections with islands creating curved right turn lanes. Americans barely have competency at four way stops, the main way who goes next is figured out is someone launching from a rolling stop before the others. There's also often hand waiving, honking, and lights flashing because people are just plain ignorant the actual law, or even common sense.

And traffic circles? Fuck that's super confusing! Americans would rather get into accidents at a four way stop than be confused in a traffic circle. That's why traffic circles are so uncommon.

Re: A Type of Road Junction that Kills Cyclists

#58

Post by cmurf »

bo1024 wrote: post #49
u801e wrote: post #36

Earlier quoted context omitted.

The US also tends to overuse stop signs when a yield (give way) sign would suffice. That is, if there is sufficient visibility of approaching traffic, coming to a complete stop is not necessary to safely yield to any conflicting traffic. Also, coming to a complete stop and then proceeding isn't sufficient to properly yield to approaching traffic. In the end, stop signs end up being treated like yield signs. The only…

Even then, they're still not treated like stop signs. Drivers blow past the sign up to the farthest possible point and only stop there, if at all. In particular they speed right over the pedestrian crossing without looking.

That's because in America you grandma can legally teach you how to drive and so you learn all her bad habits. It's a feature, not a bug. And your driving test might cover this type of intersection or it might not. The testing is like 50 out of 5000 possible questions. Again, it's a feature (of idiocy) not a bug.

I personally know maybe one other person, who knows that the location of the stop sign defines a line perpendicular to your lane and you're supposed to stop completely before this imaginary line. Almost no one knows this is the law. And sure as fuck no one actually does it.

I'd love to have a light saber for the sole purpose of cutting off everyone's goddamn front end of their car right along this imaginary line. Oh, your front seat is in the imaginary line? So sad...

Re: A Type of Road Junction that Kills Cyclists

#59

Post by ajmurmann »

maxerickson wrote: post #24
bdamm wrote: post #17

Earlier quoted context omitted.

Indeed, a stop sign would solve this, wouldn’t it? Simplist & cheapest solution first. The point about the geometry is that it doesn’t matter at which point the driver can see over the hill and brush; they still won’t see the cyclist.

The UK hates stop signs. https://en.wikipedia.org/wiki/Stop_sign#United_Kingdom

I thought only the US loved stop signs.

Re: A Type of Road Junction that Kills Cyclists

#60

Post by toomanybeersies »

jmts wrote: post #32
matte_black wrote: post #4

Wow, after all these years I finally learned the name of this phenomenon, constant bearing decreasing range. I recall a scene in the movie Sin City where two cars crash and the camera was moving in CBDR to the perpendicular car as it zoomed into the impact site. I thought it was a cool shot. Also I’ve almost hit pedestrians several times when they were obscured by my A pillar. Sometimes I wonder if I would have actua…

> Sometimes I wonder if I would have actually hit them if anyone would have believed I didn’t see them As a daily motorcyclist that also drives a car, I'm uncomfortably aware of how much of your vision the A-pillar obscures. Not to mention the passenger side one, the B-pillars, and seating. That said, it is as much my responsibility (or any road user, or pedestrian) not to put myself into a dangerous position as much…

It seems to be worse in newer cars. Most cars I've driven have been older models, pre-2000, every time I have to drive a new car, I'm always surprised at how bad the visibility is, they all have tiny rear windows and massive A pillars.

I used to own an old Datsun truck from the 1980s and the A-pillar blindspot was tiny because it had small, vertical A-pillars. A-pillars are a lot thicker and a lot more angled in newer cars.

This study [1] (from 2001) here goes into some details about A-pillar blindspots and how newer cars have worse visibility. I'm sure in the 17 years since the study was performed, cars have only gotten worse.

[1] http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.884...

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