Explaining the Railroad mileage and Track ID System

I'm a graduate student at the University of Louisville working on a study analyzing railroad hazmat accidents. We are working a data base which provides accident local based upon their relationship to graded crossing but would like to locate the accidents based upon the railroad tracks mileage markers. We are having trouble with the determining the track ID’s and the mileage system used on the tracks. Could a professional please explain the railroad track mileage methodology used (aka: Where the mileage of a track ends and begins) and track Id system?

Your help and input is greatly appreciated

Cheers
Jarivard

There is a lot of variation in the way milposts are assigned and the track is identified. Due to mergers, realignments, etc, even the mileages on a given line are sometimes inconsistent.

In many cases, mileposts were assigned based on distance from the origin point when the line was first built. In some cases, these mile markers have survived many mergers and realignments. It is more the exception than the rule, at least in my area, for mileposts to be changed when a line is reconfigured by a new owner.

Locations may be designated by the name of the line or by the particular subdivision based on a particular railroad's practices.

For example, Penn Central and Conrail kept the original "Chicago Line" designation of mileposts begining from NY City for the New York -Buffalo "Water Level Route" as built by the New York Central. CSX contined this with the prefix "QC" for this line.

The ex NYC West Shore Line has mile posts beginning at Weehawken, NJ but much of the line was removed years ago. The surviving part in the Rochester, NY area is the CSX West Shore Subdivision which begins with MP QW347.4 (at QC359.2 on the Chicago Line/Rochester Sub) and continues to MP QW368.8 which rejoins the Chicago Line at QC382.6.

But, see the discussion about D&H mileposts on this thread, for another policy:

http://www.railroad.net/forums/viewtopic.php?t=27147

I think the best descripion is that there is no standard other than the combination of a particular line or subdivion designator and a mile post location should identify a unique point on that particular railroad.

Actual mileages may not correspond to milepost due to realignments. For example, PennCentral 1974 timetable for the Chicago Line had the notation:

"The distance from MP 286 to MP 294 is 8.8 miles (the distance between each milepost is 5827 feet)"

Certainly not an ideal situation for a national database. You will probably need to compile a lot of specific data from individual railroads.

You would be lucky to find a mile that is a mile in some places. I have seen test miles that were off a couple of hundred feet.
Some are a little short and some are a little long, so maybe it all comes out in the end.

And then you have Mile Post Equations where the timetable will tell you for instance that between MP484 and MP483 is 850 feet.

Another thing to throw into the equation is track numbering. They must have been numbered by which one was there first. Sometimes track one is on this side, and sometimes on the other.

Contact the NTSB, and get a list of their accident reports. You can then purchase the ones that interest you. They come in the form of a softback book, almost like a magazine. You can request them, by carrier, geographical location, accident type, Haz-Mat release, etc. All of the legwork is there, for you. As stated, most MP's start at the railroads origin, and extend outwards, to the ends of their lines. Those accident reports include maps, diagrams of the accident site, photos, crew testimony, witness testimony, and factual findings, by the investigators. A quick way to learn the ins and outs, of accident investigation/reporting. Regards

As far as track numbering goes, except for rare instances, the tracks that go north, and east, are even numbered. South and west, are odd. Some places numbered them numerically, from one side, to the other, without regards to primary direction of operation. Rare to see it different, from that.

Apparently there is no set rules because on the NS, the south and east tracks are number one in one area and in another area, it's reversed. Don't know if it's the difference between old Conrail lines or what.

Would GPS latitude and longitudes be of any value?