From: ahk@chinet.com
bob wrote:
>On 2015-02-20 14:59:23 +0000, Adam H. Kerman said:
>>bob wrote:
>>>On 2015-02-17 16:38:27 +0000, Adam H. Kerman said:
>>>>rcp27g@gmail.com wrote:
>>>>>On Monday, 16 February 2015 16:25:47 UTC+1, Adam H. Kerman wrote:
>>>>>>bob wrote:
>>>>>>>On 2015-02-13 20:23:01 +0000, Marc Van Dyck said:
>>>>>>>>rcp27g@gmail.com explained on 13-02-15 :
>>>>>>>>>or putting in positive singalling control on others (ie where the
>>>>>>>>>crossing is protected by railway signals that aren't cleared for the
>>>>>>>>>train until the barriers are down and the crossing positively checked
>>>>>>>>>to be clear).
>>>>>>>>This is perfectly feasable but requires to order the gates to go down
>>>>>>>>at a distance that is longer than the braking distance of the train.
>>>>>>>>This means there will be a long delay between the gate going down and
>>>>>>>>the train actually passing the grade crossing.
>>>>>>>Indeed, this is the case. It is less convenient but allows for
>>>>>>>positive safety.
>>>>>>>>As it has been mentioned, motorists are unpatient creatures;
>>>>>>>>if the delay is too long, people think the gates are faulty and
>>>>>>>>start turning around them. You might end up this way with a grade
>>>>>>>>crossing that is inherently less safe, because of human nature...
>>>>>>>Solved by making the barriers block the whole road. As the crossing is
>>>>>>>positively checked to ensure the barriers are down and the crossing is
>>>>>>>clear before clearing the signals for the trains, the issue of cars
>>>>>>>being trapped within the crossing is avoided.
>>>>>>Clearing level crossings several minutes before the train
>>>>>>arrives mitigates against non-existant risk, and it's quite labor
>>>>>>intensive. How is the cost of delay justified? How is the personnel
>>>>>>cost justified?
>>>>>This "non-existant risk" just killed 6 people.
>>>>You know, I really can't stand people on Usenet who can't debate,
>>>>and therefore find it necessary to set up a straw man.
>>>Pot, meet kettle.
>>Well, no, I didn't set up a straw man, so your PKB accusation is
>>inappropriate.
>>>>She didn't violate the grade crossing minutes before the train arrived, but
>>>>within the last 15 seconds. She had a minor intrusion at about 15 seconds,
>>>>then at about 5 seconds, pulled deliberately into the path of the oncoming
>>>>train.
>>>You are contending that people will violate a crossing regardless of
>>>the state of barriers across the roadway blocking access to the
>>>crossing. I contend this is not the case.
>>Drivers drive around lowered crossing gates. There's a famous video of
>>a driver who drove around lowered crossing gates in a situation in which
>>video cameras were placed at a newly-designed grade crossing with major
>>safety improvement. A center barrier had been erected for the last 40
>>feet of the highway approaching the grade crossing, and the lowered
>>gate completely blocked that side of the highway. A motorist made the
>>decision to drive onto the wrong side of the highway to drive around
>>the lowered gates.
>Strawman.
You can't debate, AND you don't know what "strawman" means despite making
them often. It's not a straw man. It's an example of idiot behavior,
despite some traffic engineer claiming that HIS design is the greatest
thing since sliced bread and will prevent idiot behavior.
We have had collisions in which motorists drove around the grade crossing
gates by driving off the roadway, a situation that full-barrier gates
couldn't even begin to address.
>I have explicitly and specifically stated that the crossing type concerned
>here has *full* barriers across the whole roadway at both sides of the
>railway. You are describing an incident of a driver violating a crossing
>with half barriers, *not* blocking the roadway that a driver violated.
Despite the names being used, there are neither half nor full barrier
gates in the United States. Typical gates block half of the roadway plus
one third to one half of the distance into the opposing half of the road.
There aren't full barrier gates at all on public grade crossings; they can
be used at private crossings. Instead, there are separate gates on the
entrance and exit sides of the grade crossing. I don't know how full barrier
crossings are possible without manned grade crossings or remote surveillance
as full barrier crossings really would trap vehicles..
With exit barriers, they go down later than entrance barriers, to allow
the grade crossing to clear of cars. So you still have the situation in
which the entrance barriers go down earlier than at typical crossings,
dealing with traffic that would clear the grade crossing between 20 and 35
seconds before the train gets there, a period in which there's no serious
danger to address. They're a waste of money.
>>You cannot contend that a safety system can be placed at a grade crossing
>>that no driver will violate.
>I contend that drivers who are willing to drive around crossings, as a
>calculated risk, will not be willing to drive through two physical
>barriers, a process which will almost certainly case actual damage to
>their car in the process.
No one gives a fuck what your contention is, because you lack the ability
to speak for all the world's errant, incompetant, and wreckless motorists.
>>>In the collision in question here, the barrier came down *on top of*
>>>the vehicle. That means the vehicle was *already* inside the crossing
>>>(as defined by the area bounded by the road barriers) *before* the
>>>barriers came down.
>>It means that she violated the grade crossing, ignoring the flashers and
>>bells AND the gate that was in the process of being lowered. If anything,
>>a gate being lowered moves and truly catches the driver's eye, so that
>>actually adds a bit of safety.
>I haven't heard an account of the events leading up to the events in
>this specific crash about how the driver ended up under the barrier,
>and as people have died in this crash, I don't want to enter into
>speculation.
Then you've simply chosen the course of willful blindness and you should
keep your ignorant opinions to yourself. There has been no shortage of
discussion in the news, and you have been provided with links to excellent
news coverage on Usenet in this thread and others.
>>A crossing gate isn't a genuine barrier as they are designed to be
>>flexible and to break readily so that vehicles are NEVER trapped. The
>>main purpose of the crossing gate is to put additional flashers at
>>the driver's eye level, at least when it's lowered.
>In a crossing where the trains are controlled in a way that prevents a
>collision in the event of a car or other road users becomes trapped on
>the crossing,
Listen to me, moron: There is no such thing as a signalling system that
prevents every intrusion and all conflict. The best you can do is reduce
the likelihood of certain types of intrusions and collisions given past
experience or a given set of assumptions. You have no ability to predict
the future.
There still has to be enough time for the train to stop BEFORE the collision
occurs, because only in your tiny mind has the law of conservation of
momentum been repealed.
>there is no safety hazard associated with vehicles becoming trapped on
>the crossing: the train stops, the barriers are raised, and the vehicle
>escapes. If there is no need to allow trapped vehicles to break through,
>the barriers can be made much more robust (and obviously so).
All that requires remote surveillance or manned crossings. Stop skipping
necessary parts of the story.
>>>I would suggest that, while some drivers will enter crossings with the
>>>barriers up even if the lights/sound warnigns are active, and will drive
>>>around partial barriers (plenty of youtube videos show this taking place),
>>>they are far far less likely to drive *through* a barrier that is blocking
>>>the road.
>>That's nice, but you're backing off your earlier contention that drivers
>>won't violate the grade crossing given the state of barriers across
>>the roadway. So you still think some drivers will violate the grade crossing.
>It has never been my contention that drivers will not attempt to
>violate a crossing in which the barriers are not yet fully down across
>the whole width of the roadway. My contention is that in a crossing
>where the trains signals protect the crossing, in the event that the
>crossing is violated, the result of the violation will not be a
>collision.
Must be nice to live in your little mind.
>>>>The system you advocated addresses a period of minutes before the
>>>>train arrives in which there really isn't any danger of collision.
>>>The difference between the crossing types I have described is not down
>>>to the method used to keep cars off the crossing, but the method used
>>>to keep *trains* off the crossing. In the crossing involved in this
>>>collision, there is *no* method to stop trains from crossing.
>>Now you're trying to imply that trains can stop on a dime. Lovely.
>>As I've already explained about PTC grade crossings just recently installed
>>between Chicago and St. Louis, they have to be active many minutes before
>>the train gets there so that the train can be thrown into emergency and,
>>even then, it'll reduce speed down to 15 mph. Still addressing the issue
>>of grade crossing violations that occur minutes before the train gets
>>there, and not within the last 10 seconds as with the situation that
>>we are discussing. It addresses a truck that stalled within the grade
>>crossing minutes before the train gets there, nothing else.
>Another straw man.
It's not a straw man, you stupid moron. It's an explanation of what the
traffic engineers and the railroad signalling engineers had to do in order
to get the system to work, and how far in advance of the train's arrival
the signals must activate in order to greatly reduce the train's speed to
mitigate the inevitable collision.
You continue to ignore the basic fact that vehicles have to be completely
off the grade crossing a significant amount of time before the train arrives
for any of this to work, because it takes a long time to stop a train or
slow it down to 15 mph.
>I am not describing a crossing where the failure of the railway signalling
>to clear for the train still results in the train passing the crossing
>at 15 mph.
If the train had to stop in emergency, then the signals have to activate
even earlier, which makes it all even less cost effective for the tiny risk
being addressed. It's not failure, you blithering idiot, but mitigation,
given that the collision would be less serious at 15 mph than at 100 or 125.
Stopping the train or slowing it to 15 mph, there will still be passengers
on board getting injured.
>I am describing a crossing where, in the event of the crossing not being
>found to be clear in the intended manner, the train will be brought to
>a stop, with a normal service brake (not emergency), with distance to
>spare before the crossing.
A human being using remote surveillance has to find the crossing not in
the clear. And if the train is slowed to a stop without emergency braking,
then the crossing must be clear still longer in advance of the train's
arrival, again addressing a little tiny risk.
You're just too stupid. More snipping, not reading any more.
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