Monday, March 13, 2017

Game of Chance: The Grade-Crossing Accident in Biloxi


One of the first safety issues faced by the early railroad engineers (meaning the designers, as well as the guys who drove the trains) was how to handle grade crossings:  the place where a railroad line intersects a surface road.  The only foolproof way to handle such an intersection is to build a bridge so the foot or wheel traffic never obstructs the rail line.  Bridges are expensive, though, so in the twentieth century in the U. S. most grade crossings were simply equipped with warning signs and signals, and the railroads and local road authorities hoped for the best.  As the accident on Mar. 7 in Biloxi, Mississippi proved, the best is sometimes pretty bad.

Biloxi and the surrounding area is a magnet for retirees who like to spice up their lives with games of chance, and so tour buses transporting seniors from as far away as Texas and other states are a common sight in town.  A CSX railroad line runs east-west through town, at a level of a few feet above the surrounding flat coastal land, and crosses Main Street at a grade crossing.  When the crossing was built, probably in the early 1900s, the longest wheeled vehicle likely to cross it was no more than about twenty feet long, and the slight rise of the rail-line level from the street on either side of the tracks presented no problem.  But with the development of trailers and buses later in the century that were fifty feet long or more, these raised grade crossings presented a hazard, because vehicles with a long wheelbase can scrape the rails and lose traction, getting stuck on the tracks.  And at the intersection in question, there have been numerous accidents caused by just such a problem since the 1970s, both fatal and non-fatal.

On Tuesday, March 7, the driver of a tour bus transporting vacationers from the Bastrop, Texas Senior Center was apparently deviating from his bus company's prescribed route when he approached the CSX crossing on Main Street.  And just as many other drivers of long vehicles discovered, his bus wasn't going to make it.  According to reports, the bus was stuck for about five minutes before a three-locomotive freight train hit it, carrying the bus about 200 feet down the tracks.  Although riders had begun to flee the bus before the collision, many were still trapped inside when the train struck.  Four people were killed, including a couple from Lockhart, not far from where I live.  Thirty-five people were injured, several critically.

Most people know that trains can't stop on a dime, or even a quarter-mile row of dollar bills.  The laws of physics make it almost impossible to safely dissipate the huge amount of energy represented by a loaded train moving, say, 25 miles per hour (as the CSX freight was before the engineer saw the bus stuck on the tracks) without taking many seconds and hundreds of feet to do it in.  So realistically, it's up to drivers to stay out of the way of trains on grade-crossing tracks.

Railroad companies have tried all kinds of things to prevent people from getting stuck on tracks:  bells, gates, signs warning that long vehicles can get stuck (there were such signs posted at the Main Street crossing), even heavy-handed color movies displaying in grim detail the consequences of taking chances with trains.  (I watched one of those movies on a rainy day in elementary school when the teacher was desperate to keep us distracted during recess, and it gave me nightmares.)  But if drivers ignore warning signs and, once a bus is stuck, fail to evacuate it promptly, the inevitable is going to happen sooner or later, as it did last week in Biloxi.

As an article in the Austin American-Statesman pointed out, not even the new and costly Positive Train Control (PTC) system now being installed by railroads across the U. S. would have prevented this accident.  PTC is a semi-automated system that will prevent head-on train-train collisions and will regulate speeds if the human operator gets careless.  This will make passenger trains safer and reduce the number of freight-train accidents.  But even PTC can't keep people from getting stuck on the tracks at grade crossings. 

The overall incidence of fatal accidents involving U. S. railroads has decreased since the 1990s, but until grade crossings with humps such as the one in Biloxi are eliminated, there is always the chance of a careless truck or bus driver coming along and getting stuck on the tracks.  Towns that can afford the space and expense are replacing grade crossings with overpasses that both improve traffic flow and eliminate the safety hazard, but as the American Society of Civil Engineers has been fond of pointing out for decades, America is way behind in infrastructure improvements such as these. 

Right here in San Marcos, we have two frequently-used rail lines that used to cut the town in two at the three major intersections of east-west roadways and railroad lines.  And on rare occasions, a long train or trains would simply stop at these crossings, making it difficult or impossible for emergency vehicles to get from the west side of town to the hospital on the east side.  About eight years ago, the city built an overpass at the grade crossing nearest the hospital, and currently another bridge is being built over the second of the three major crossings.  But this will still leave an old-fashioned humped grade crossing near the middle of town, which fortunately is not situated on a major traffic artery.  Still, there is always a chance that a wayward truck or bus will get stuck there, although such an incident hasn't happened in the seventeen years we've lived here.

Perhaps this whole issue of grade-crossing hazards will fade into the past as autonomous passsenger vehicles come into general use.  One hopes that the programmers of those vehicles will build in a fail-safe way to keep them away from railroad tracks where the vehicle is likely to get stuck, and to obey crossing warnings.  But unless the passenger is completely unable to influence the car's motion in any way, there will still be people who will override the safety features and try to cross against warning signs and signals—and they will be taking a chance they shouldn't try to take.

Sources:  I referred to articles on the accident published on the site heavy.com at http://heavy.com/news/2017/03/biloxi-bus-train-crash-accident-deaths-toll-injuries-derailed-killed-mississippi-update-how/ and ABC-TV News, New York at http://abc7ny.com/news/history-of-deadly-mississippi-train-crash-site-a-focus-of-investigation/1790941/, as well as a print report "Biloxi bus crash highlights limits of high-tech safety measures for trains," by Ben Wear carried in the Mar. 12, 2017 edition of the Austin American-Statesman, pp. A1 and A6.  The gripping drama "The Last Clear Chance" (produced by the Union Pacific Railroad in 1959) can be viewed at the Prelinger Archive of ephemeral films at https://archive.org/details/0845_Last_Clear_Chance_The_08_29_26_00. 

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