Geometry is Killing us. Literally at one intersection.
#26
Senior Member
Join Date: Jan 2010
Posts: 1,811
Mentioned: 3 Post(s)
Tagged: 0 Thread(s)
Quoted: 184 Post(s)
Liked 353 Times
in
90 Posts
I should point out that the crash in the scenario Joey is using as an example is different; it wll lead to a single vehicle crash. Cyclist will veer toward the right as he focuses all his attention to the right hoping to see that woman. This rightward veer will take him into the tree. Woman walks past unharmed.
Ben
Ben
#27
Senior Member
Join Date: Sep 2007
Location: Far beyond the pale horizon.
Posts: 14,278
Mentioned: 31 Post(s)
Tagged: 0 Thread(s)
Quoted: 4260 Post(s)
Liked 1,363 Times
in
945 Posts
This street view in the following article shows a yield. The Google satellite view shows a stop.
https://jalopnik.com/the-deadly-phen...-ed-1821999343
This rewording of the article makes the point more clear.
https://boingboing.net/2018/01/10/69-degrees.html
===================
It seems likely that the drivers wouldn't even be looking at the cross road in the purple and blue zones (maybe, even later). Even if there wasn't an obstruction (the A pillar), they might not be able to see a cyclist at those distances.
===================
Keep in mind that the idea is that there are three things that combined in this case to make the collisions more likely.
1- The approximate relative speeds of the to.
2- The angle (69') that would require the cyclist to look back a bit to be able to see the approaching car.
3- Where the A pillar happened to be (relative to the other things).
It appears the intersection now has a stop sign (and used to have a yield). We don't know when that change was made or what the status was when the collisions occurred.
We only know about the collisions with cyclists. We know nothing about whether there were other collisions there.
https://jalopnik.com/the-deadly-phen...-ed-1821999343
This rewording of the article makes the point more clear.
https://boingboing.net/2018/01/10/69-degrees.html
===================
It seems likely that the drivers wouldn't even be looking at the cross road in the purple and blue zones (maybe, even later). Even if there wasn't an obstruction (the A pillar), they might not be able to see a cyclist at those distances.
===================
Keep in mind that the idea is that there are three things that combined in this case to make the collisions more likely.
1- The approximate relative speeds of the to.
2- The angle (69') that would require the cyclist to look back a bit to be able to see the approaching car.
3- Where the A pillar happened to be (relative to the other things).
It appears the intersection now has a stop sign (and used to have a yield). We don't know when that change was made or what the status was when the collisions occurred.
We only know about the collisions with cyclists. We know nothing about whether there were other collisions there.
Last edited by njkayaker; 01-12-18 at 08:41 AM.
#28
Senior Member
Join Date: Nov 2014
Location: Eugene, Oregon, USA
Posts: 27,547
Mentioned: 217 Post(s)
Tagged: 0 Thread(s)
Quoted: 18378 Post(s)
Liked 4,512 Times
in
3,354 Posts
Google Street View, N/S Beaulieu shows stop sights, Date June 2017. Also two little bike symbols in front of the stop line.
https://www.google.com/maps/@50.8631...i6656?hl=en-US
Google Street View, E/W shows yield signs, Date May 2016. Did someone plant a sign directly in front of the yield sign? Also no bicycle symbols.
https://www.google.com/maps/@50.8631...i6656?hl=en-US
The first two accidents were in 2011 and 2012.
The third accident was in December 2016, between the two street images.
Presumably the first two accidents had the yield sign. We don't know what transpired between May 2016 and December 2016, but I presume the stop signs and bicycle symbols came after the third accident.
I don't think I've ever seen an intersection on a rural road without a stop sign, although occasionally one finds urban intersections with either yield signs, or no markings at all.
I think there may be too much temptation to hit rural yield signs at speed... and not really yield at all.
Even if one does a "rolling stop", one usually reduces speed for stops, thus no longer "constant velocity".
#29
Senior Member
Join Date: Sep 2007
Location: Far beyond the pale horizon.
Posts: 14,278
Mentioned: 31 Post(s)
Tagged: 0 Thread(s)
Quoted: 4260 Post(s)
Liked 1,363 Times
in
945 Posts
Interesting.
Google Street View, N/S Beaulieu shows stop sights, Date June 2017. Also two little bike symbols in front of the stop line.
https://www.google.com/maps/@50.8631...i6656?hl=en-US
Google Street View, N/S Beaulieu shows stop sights, Date June 2017. Also two little bike symbols in front of the stop line.
https://www.google.com/maps/@50.8631...i6656?hl=en-US
It's also the sort of road where drivers are going to be focused straight ahead.
Google Street View, E/W shows yield signs, Date May 2016. Did someone plant a sign directly in front of the yield sign? Also no bicycle symbols.
https://www.google.com/maps/@50.8631...i6656?hl=en-US
That sign was moved to the opposite side of the road.
=================
In both images, there are cyclists approaching from the West.
Last edited by njkayaker; 01-12-18 at 08:04 AM.
#31
Senior Member
Join Date: Sep 2007
Location: Far beyond the pale horizon.
Posts: 14,278
Mentioned: 31 Post(s)
Tagged: 0 Thread(s)
Quoted: 4260 Post(s)
Liked 1,363 Times
in
945 Posts
(Anyway, in this case, there is a small hill and bushes that obscure the view.)
The reality is that humans are not good at calculating the vectors involved and predicting the future positions of themselves and crossing objects. When the speeds and angles are right a crossing object will appear to stay in the same place (angle in the field of vision) and so it's very easy to underestimate it's speed (it's not moving at all, right?) and not be aware if the risk of collision.
The entire point is the fact that the bearing angle isn't changing means collision is certain.
Last edited by njkayaker; 01-12-18 at 08:37 AM.
#32
Senior Member
Join Date: Jul 2008
Location: 25 miles northwest of Boston
Posts: 29,552
Bikes: Bottecchia Sprint, GT Timberline 29r, Marin Muirwoods 29er, Trek FX Alpha 7.0
Mentioned: 112 Post(s)
Tagged: 0 Thread(s)
Quoted: 5224 Post(s)
Liked 3,584 Times
in
2,344 Posts
beautiful women have been stooping traffic for a long time & many leave us breathless
#33
Senior Member
Join Date: Sep 2013
Location: Massachusetts
Posts: 4,530
Mentioned: 34 Post(s)
Tagged: 0 Thread(s)
Quoted: 2112 Post(s)
Liked 663 Times
in
443 Posts
An interesting point is that, due to the acute angle, the car is approaching the cyclist slightly from behind.
(Anyway, in this case, there is a small hill and bushes that obscure the view.)
All you have to note is that the bearing angle between you and the other vessel is not changing.
The entire point is the fact that the bearing angle isn't changing means collision is certain.
(Anyway, in this case, there is a small hill and bushes that obscure the view.)
All you have to note is that the bearing angle between you and the other vessel is not changing.
The entire point is the fact that the bearing angle isn't changing means collision is certain.
So now only people who do not slow down at all and blow through the stop sign (and their victims) will find themselves in a CBDR.
-mr. bill
#34
Senior Member
Join Date: Sep 2007
Location: Far beyond the pale horizon.
Posts: 14,278
Mentioned: 31 Post(s)
Tagged: 0 Thread(s)
Quoted: 4260 Post(s)
Liked 1,363 Times
in
945 Posts
There's now a STOP sign at the intersection.
Heck, there was a hill and bushes blocking the view.
CBDR isn't that useful a concept for driving anyway.
Last edited by njkayaker; 01-12-18 at 12:22 PM.
#35
Senior Member
Join Date: Jul 2006
Location: San Jose (Willow Glen) Ca
Posts: 9,847
Bikes: Kirk Custom JK Special, '84 Team Miyata,(dura ace old school) 80?? SR Semi-Pro 600 Arabesque
Mentioned: 106 Post(s)
Tagged: 0 Thread(s)
Quoted: 2338 Post(s)
Liked 2,827 Times
in
1,543 Posts
Oh, I can imagine the return of the bubble shaped Pacer.
Perhaps a little more work to reduce the pillars. There are quite a few cars with frameless windows on the doors, but still have the main pillars.
That is one thing I dislike about Mom's Prius, really bad rear visibility
Perhaps a little more work to reduce the pillars. There are quite a few cars with frameless windows on the doors, but still have the main pillars.
That is one thing I dislike about Mom's Prius, really bad rear visibility
it personally bugs me that most newer cars have much less visibility due to design and safety requirements than older cars. Part of the reason I am still driving a 97 bmw
__________________
Life is too short not to ride the best bike you have, as much as you can
(looking for Torpado Super light frame/fork or for Raleigh International frame fork 58cm)
Life is too short not to ride the best bike you have, as much as you can
(looking for Torpado Super light frame/fork or for Raleigh International frame fork 58cm)
#36
genec
Join Date: Sep 2004
Location: West Coast
Posts: 27,079
Bikes: custom built, sannino, beachbike, giant trance x2
Mentioned: 86 Post(s)
Tagged: 0 Thread(s)
Quoted: 13658 Post(s)
Liked 4,532 Times
in
3,158 Posts
Heck, they wouldn't even implement the "change one road" solution... much less make a round-a-bout.
The fact is the local authorities don't give a hoot about injured or dead cyclists... any more than society at large.
To quote a comment offered by one of the readers of the site:
As a society, we tend to give preferential treatment to motorists... unless drugs or alcohol are involved. This all comes from the "oops, it was an "accident" mentality. In the case of one dead victim mentioned in the OP link... there was plenty of evidence to indicate the driver never even slowed down, in spite of there being a "Give Way" zone. (cheap version of a stop sign... )
In fact the driver was charged with causing death by dangerous driving and pleaded guilty to causing death by careless driving, but was found not guilty of the more serious offence by a jury despite having driven through the junction’s “Give Way” line at 37mph without slowing.
The fact is the local authorities don't give a hoot about injured or dead cyclists... any more than society at large.
To quote a comment offered by one of the readers of the site:
I agree that blind spots, CBDR, stop signs, give way signs, junction designs are part of the problem, here and at similar junctions. The real problem though is the way people who drive a vehicle and kill someone else are allowed to simply hang their head and say sorry, opps, slap my wrist, give me a fine, possibly even stop me driving for a wee while, maybe lock me up if I’ve very very naughty.
Maybe some properly scary punishments, like lifetime driving bans, jail terms similar to manslaughter?
Maybe some properly scary punishments, like lifetime driving bans, jail terms similar to manslaughter?
In fact the driver was charged with causing death by dangerous driving and pleaded guilty to causing death by careless driving, but was found not guilty of the more serious offence by a jury despite having driven through the junction’s “Give Way” line at 37mph without slowing.
#37
genec
Join Date: Sep 2004
Location: West Coast
Posts: 27,079
Bikes: custom built, sannino, beachbike, giant trance x2
Mentioned: 86 Post(s)
Tagged: 0 Thread(s)
Quoted: 13658 Post(s)
Liked 4,532 Times
in
3,158 Posts
Thanks to Joey, for bringing this up... so other cyclists may think about it.
As a boater and boat racer, I have faced the CBRD situation quite a bit, and am quite familiar with it.
As a boater and boat racer, I have faced the CBRD situation quite a bit, and am quite familiar with it.
#38
Banned
Join Date: Apr 2008
Posts: 1,341
Mentioned: 4 Post(s)
Tagged: 0 Thread(s)
Quoted: 959 Post(s)
Likes: 0
Liked 0 Times
in
0 Posts
...
The fact is the local authorities don't give a hoot about injured or dead cyclists... any more than society at large.
To quote a comment offered by one of the readers of the site:
As a society, we tend to give preferential treatment to motorists... unless drugs or alcohol are involved. This all comes from the "oops, it was an "accident" mentality. In the case of one dead victim mentioned in the OP link... there was plenty of evidence to indicate the driver never even slowed down, in spite of there being a "Give Way" zone. (cheap version of a stop sign... )
In fact the driver was charged with causing death by dangerous driving and pleaded guilty to causing death by careless driving, but was found not guilty of the more serious offence by a jury despite having driven through the junction’s “Give Way” line at 37mph without slowing.
The fact is the local authorities don't give a hoot about injured or dead cyclists... any more than society at large.
To quote a comment offered by one of the readers of the site:
As a society, we tend to give preferential treatment to motorists... unless drugs or alcohol are involved. This all comes from the "oops, it was an "accident" mentality. In the case of one dead victim mentioned in the OP link... there was plenty of evidence to indicate the driver never even slowed down, in spite of there being a "Give Way" zone. (cheap version of a stop sign... )
In fact the driver was charged with causing death by dangerous driving and pleaded guilty to causing death by careless driving, but was found not guilty of the more serious offence by a jury despite having driven through the junction’s “Give Way” line at 37mph without slowing.
Last edited by Ninety5rpm; 01-12-18 at 02:44 PM. Reason: improve wording
#39
Senior Member
Join Date: Nov 2014
Location: Eugene, Oregon, USA
Posts: 27,547
Mentioned: 217 Post(s)
Tagged: 0 Thread(s)
Quoted: 18378 Post(s)
Liked 4,512 Times
in
3,354 Posts
As mentioned above, sometime around the time of the third accident (second fatality), the yield signs were replaced with stop signs, and bike images were painted on the road.
Even if drivers roll through the stop signs, it is less likely that they'll be rolling through them at constant velocity without looking.
So, re-routing the roads may not have been necessary.
I find yield signs, and unmarked intersections rare in urban areas here in the USA. But, I don't think I've ever seen a yield sign in rural areas in the USA. And this very accident may well be the reason. Rolling stop or not, people are going faster through yield signs, and just don't pay as much attention.
Oh, perhaps there are unmarked street corners on gravel roads on forest service roads in the mountains. But even in that case, there often is a main street and a side street with pretty obvious precedence.
Hopefully the British will actually evaluate other intersections. Rather than adding costly, and potentially dangerous offset intersections, or millions of roundabouts, they should just replace all of the yield signs with stop signs. Also stop doing that silly putting a sign directly in front of a stop/yield sign (shared sign post instead?)
#40
genec
Join Date: Sep 2004
Location: West Coast
Posts: 27,079
Bikes: custom built, sannino, beachbike, giant trance x2
Mentioned: 86 Post(s)
Tagged: 0 Thread(s)
Quoted: 13658 Post(s)
Liked 4,532 Times
in
3,158 Posts
If avoiding crashes is not enough motivation for them to drive more carefully, then obscure threats of remotely possible prison time are not going to make a difference (I say "remotely possible" because the odds that any one person will crash and kill someone is remotely low, therefore the having to suffer the consequences stemming from killing someone due to careless driving is only remotely possible for any one person).
#41
Banned
Join Date: Apr 2008
Posts: 1,341
Mentioned: 4 Post(s)
Tagged: 0 Thread(s)
Quoted: 959 Post(s)
Likes: 0
Liked 0 Times
in
0 Posts
There's a justice consideration too. It's one thing if they were doing something blatantly wrong like DUI or texting. But if it's just the result of an honest mistake - humans are inherently fallible - we generally don't punish in our society. That's fundamental to who we are.
#42
genec
Join Date: Sep 2004
Location: West Coast
Posts: 27,079
Bikes: custom built, sannino, beachbike, giant trance x2
Mentioned: 86 Post(s)
Tagged: 0 Thread(s)
Quoted: 13658 Post(s)
Liked 4,532 Times
in
3,158 Posts
There's a justice consideration too. It's one thing if they were doing something blatantly wrong like DUI or texting. But if it's just the result of an honest mistake - humans are inherently fallible - we generally don't punish in our society. That's fundamental to who we are.
As you said, it doesn't happen often (only 30,000 - 40,000 deaths a year, right?)
So perhaps the threat of loss of driving privilege might just reduce the "honest mistakes" just a wee bit.
If you want to drive in Germany you need to be dedicated, which makes for better drivers. And better drivers means fewer accidents, fewer accidents means fewer deaths: Germany has far fewer motor vehicle-related fatalities (per 100,000 people) than the US.
To get a license in Germany, you are required to take tons of driving lessons, including several where you're taken on the actual Autobahn and put into real, high-speed traffic. Drivers must receive basic first-aid training, and on top of that, you still have an incredibly difficult multiple choice exam and the road test.
Germany?s Autobahn vs US highways: COMPARED - Business Insider
https://en.wikipedia.org/wiki/List_o...ted_death_rate
#43
Senior Member
Join Date: Jul 2010
Location: Stephenville TX
Posts: 3,697
Bikes: 2010 Trek 7100
Mentioned: 6 Post(s)
Tagged: 0 Thread(s)
Quoted: 697 Post(s)
Likes: 0
Liked 3 Times
in
3 Posts
There's a justice consideration too. It's one thing if they were doing something blatantly wrong like DUI or texting. But if it's just the result of an honest mistake - humans are inherently fallible - we generally don't punish in our society. That's fundamental to who we are.
Right. I personally think about 40% of the bad driving I see daily should be upgraded to the criminally negligent category and another 5% should be higher than that; it certainly would be if someone handled a gun with the attitude they demonstrate behind the wheel. The problem, IMO, is that as far as I can tell, the theoretical "ordinary person" has followed actual societal norms in becoming an unacceptably careless driver, so the standard devolves to permit a much lower standard of care.
#44
Senior Member
Join Date: Nov 2014
Location: Eugene, Oregon, USA
Posts: 27,547
Mentioned: 217 Post(s)
Tagged: 0 Thread(s)
Quoted: 18378 Post(s)
Liked 4,512 Times
in
3,354 Posts
Of course, the issue brought up in this topic are car designs with blind spots, and street designs with through yield signs that people aren't paying enough attention to.
One can complain all one wants about bad drivers, but part of the government's role is to look at factors that could contribute to accidents, and to use this knowledge to encourage better driving, and to modify streets to be safer.
It is likely that that little change from a yield to a stop in 2016/2017 will make a significant safety improvement at that intersection, with simply the cost of a new sign, and a bucket of paint. And, perhaps someone will also be paying enough attention to improving designs of other intersections too. Those yield signs are a cool idea, but I'm not sure they're safe, and probably of minimal actual benefit.
One can complain all one wants about bad drivers, but part of the government's role is to look at factors that could contribute to accidents, and to use this knowledge to encourage better driving, and to modify streets to be safer.
It is likely that that little change from a yield to a stop in 2016/2017 will make a significant safety improvement at that intersection, with simply the cost of a new sign, and a bucket of paint. And, perhaps someone will also be paying enough attention to improving designs of other intersections too. Those yield signs are a cool idea, but I'm not sure they're safe, and probably of minimal actual benefit.
#45
Senior Member
Join Date: Sep 2007
Location: Far beyond the pale horizon.
Posts: 14,278
Mentioned: 31 Post(s)
Tagged: 0 Thread(s)
Quoted: 4260 Post(s)
Liked 1,363 Times
in
945 Posts
If you want to drive in Germany you need to be dedicated, which makes for better drivers. And better drivers means fewer accidents, fewer accidents means fewer deaths: Germany has far fewer motor vehicle-related fatalities (per 100,000 people) than the US.
83MM 3200 deaths 8437* mpy 38 deaths/MM
320MM 32479 deaths 13476 mpy 101 deaths/MM
* this figure is from 2002 (kinda old).
The roads are different too.
CBRD or the pillar visibility might have had nothing to do with this.
There's a hill and bushes obscuring the view and drivers are mostly going to be looking forward anyway.
Last edited by njkayaker; 01-13-18 at 11:11 AM.
#46
genec
Join Date: Sep 2004
Location: West Coast
Posts: 27,079
Bikes: custom built, sannino, beachbike, giant trance x2
Mentioned: 86 Post(s)
Tagged: 0 Thread(s)
Quoted: 13658 Post(s)
Liked 4,532 Times
in
3,158 Posts
#47
Senior Member
Join Date: Sep 2007
Location: Far beyond the pale horizon.
Posts: 14,278
Mentioned: 31 Post(s)
Tagged: 0 Thread(s)
Quoted: 4260 Post(s)
Liked 1,363 Times
in
945 Posts
No, the hill and bushes don't obscure the yield sign (never said they did).
I mentioned that the issue was the yield sign and I was the one who pointed out that it's now a stop sign.
I was talking about the CRBD stuff, which has nothing to do with the yield sign either.
CRBD doesn't seem to really come into play driving anyway.
Last edited by njkayaker; 01-13-18 at 11:42 AM.
#48
genec
Join Date: Sep 2004
Location: West Coast
Posts: 27,079
Bikes: custom built, sannino, beachbike, giant trance x2
Mentioned: 86 Post(s)
Tagged: 0 Thread(s)
Quoted: 13658 Post(s)
Liked 4,532 Times
in
3,158 Posts
Did you miss the sentence before the one you quoted?
No, the hill and bushes don't obscure the yield sign (never said they did).
I mentioned that the issue was the yield sign and I was the one who pointed out that it's now a stop sign.
I was talking about the CRBD stuff, which has nothing to do with the yield sign either.
CRBD doesn't seem to really come into play driving anyway.
No, the hill and bushes don't obscure the yield sign (never said they did).
I mentioned that the issue was the yield sign and I was the one who pointed out that it's now a stop sign.
I was talking about the CRBD stuff, which has nothing to do with the yield sign either.
CRBD doesn't seem to really come into play driving anyway.
Perhaps DRIVERS don't do this much, but then it has been long established that DRIVERS are often not great at their task.
#49
Senior Member
Join Date: Apr 2009
Location: New Rochelle, NY
Posts: 38,725
Bikes: too many bikes from 1967 10s (5x2)Frejus to a Sumitomo Ti/Chorus aluminum 10s (10x2), plus one non-susp mtn bike I use as my commuter
Mentioned: 140 Post(s)
Tagged: 1 Thread(s)
Quoted: 5791 Post(s)
Liked 2,581 Times
in
1,431 Posts
It's CBDR
It might help if you spell it out for those not familiar with the term, which I've only seen in maritime applications.
It's Constant Bearing, Diminishing Range and is what the article was talking about, though compounded by the pillar.
In any case, CBDR works both ways, so we might consider it from the cyclist's perspective and apply it to avoid in being complicit in our own death.
Even if a driver can't see you hidden behind the roof pillar, you have no obstruction, and can clearly see him. CBDR applies, so if the car stays at the same angle in your field of vision, you are going to collide. Of course you know he has a stop sign and you have the right of way, but that doesn't mean you're safe unless he actually stops.
Given the speeds and distances, bicyclists don't have to slow before confirming that the car is preparing to stop. Unless he's planning to do a hard stop at the sign a driver will begin to slow in advance, which will cause his position to move back in your field of vision. Absent that cue, assume that you must make the adjustment to avoid a collision.
It's a fatal mistake to assume that the other guy will do what's needed to avoid a collision, even when you clearly have the right of way. Ultimately we have to accept responsibility for our own safety, for the simple reason that we have the most to lose.
__________________
FB
Chain-L site
An ounce of diagnosis is worth a pound of cure.
Just because I'm tired of arguing, doesn't mean you're right.
“One accurate measurement is worth a thousand expert opinions” - Adm Grace Murray Hopper - USN
WARNING, I'm from New York. Thin skinned people should maintain safe distance.
FB
Chain-L site
An ounce of diagnosis is worth a pound of cure.
Just because I'm tired of arguing, doesn't mean you're right.
“One accurate measurement is worth a thousand expert opinions” - Adm Grace Murray Hopper - USN
WARNING, I'm from New York. Thin skinned people should maintain safe distance.
Last edited by FBinNY; 01-13-18 at 12:01 PM.
#50
Senior Member
Join Date: Sep 2007
Location: Far beyond the pale horizon.
Posts: 14,278
Mentioned: 31 Post(s)
Tagged: 0 Thread(s)
Quoted: 4260 Post(s)
Liked 1,363 Times
in
945 Posts
That's done at a much shorter distance than in the situation being discussed. That's able to be done without any notion of "bearing". You should already know that.