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[quote user="Falcon48"] In response to Bucyrus' post of 8/13 and other posts speculating on the amount of time the driver had to react, NTSB reports that its investigators documented that the sight distance on the section of roadway leading up to the grade crossing from the truck driver's direction of travel was over 1 mile (not 900 feet).  See <a href="http://www.ntsb.gov/investigations/2011/miriam_nv.html">http://www.ntsb.gov/investigations/2011/miriam_nv.html</a> .  I think it is safe to regard their conclusion as authoritative. That means that the driver had the entire acrtivation time of the crossing signals as advance warning of the approach of the train (20-25 seconds, not 8.76 seconds). Also, according to news reports, the drivers of two following trucks saw the signals and were slowing for the crossing (in other words, they could see it), and questioned why the first driver had not done so. <div style="clear:both;"></div> [/quote] A lot of numbers have been crunched in this thread, but the one unresolved question is the distance from which the crossing signals can be seen.  Although there is a 30-degree curve 900 feet south of the crossing, there is a possibility of projecting the crossing flasher beam into the highway south of that curve.  One way to do it is to use lamps that have that have a beam-spread wide enough.  I don’t know if spreading the beam compromises its strength.  Another way would be to use multiple lamps, so some are aimed down the highway between the curve and the crossing, and the other lamps are turned 30-degrees so they aim down the highway south of the curve.  In any case, it would be possible to project the signals beyond the curve.  If that is the case, then my calculation of there being only a 2.92 second warning for a truck such as the one in the crash, traveling at 70 mph, is incorrect.     <o:p></o:p> I had a phone conversation with the Public Information Officer of the Nevada DOT, and ran this 2.92-second calculation past him, and he said he was unqualified to confirm or refute my analysis.  He assured me that other people in their organization were qualified to address my analysis, and that they would do so if asked.  I sent them a message inquiring about this on 8/16, and am still awaiting their reply.  <o:p></o:p> In some of the news coverage of this crash, investigators stated that the lights were visible from ½ mile.  Whether that is actually the case at this crossing through the curve in the highway, or whether it is simply the straight-line projection specification of the light beam, I don’t know.  The Public Information Officer of NVDOT says the signal lamps meet the requirement of being able to be seen from 2000 feet.   <o:p></o:p> The NTSB preliminary report linked above by Falcoln48, in its opening statement, says this:   “Investigators have documented that the sight distance on the section of roadway leading up to the grade crossing from the truck driver’s direction of travel was over 1 mile.”  <o:p></o:p> However, this NTSB statement needs clarification, because the language of it strikes me as purposely vague.  For example, if there were nothing blocking the field of vision between a person and the crossing 20 miles away, you could say that the sight distance was 20 miles.  I want to know how many feet down that highway a person with good vision can see the flashing lights of the crossing.  <o:p></o:p> Also interesting is the fact that this one technical detail given in the opening statement is left out of the language of the preliminary report.  And yet that preliminary report contains all of the other details necessary to describe the circumstances of the crash.  It repeats many of the details given in the opening statement, but not the visibility distance of the crossing upon approach.  It appears, as one would expect, that the preliminary report is an elaboration of the opening statement.  So it seems odd to give a pertinent detail in the opening statement and then leave it out of the preliminary report, which includes all of the other pertinent details.   <o:p></o:p> Therefore, I would regard the NTSB finding to be authoritative, but I would first have to know what the finding means.  So I would not jump to the conclusion that a driver has a warning of 20-25 seconds until the NTSB actually says that.  Also, the preliminary report does say that the information is preliminary and may be corrected or supplemented during the course of the investigation.    <o:p></o:p> I would also not conclude that warning was adequate simply because the two following drivers reacted in time.  For one thing, they were not on the same collision course with the train as the first truck.  But aside from that, I am not saying that the driver was blameless.  He obviously was negligent.  Even if my 2.92-second analysis is correct, that is still enough time to see the danger.  The truck driver waited past that warning, but that does not mean that every driver will do that.  <o:p></o:p> Throughout this thread, my point has not been to vindicate the truck driver, although the tread title may imply that.  In fact, if I had somehow learned the details of this crossing setup, I would be making my point about this even if this crash had not occurred.  My concern is about the danger of this crossing.
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