The National Significant Risk Threshold (NSRT) is an average of the risk indexes for gated public crossings nationwide where train horns are routinely sounded. The NSRT API may be used to download and review the specific crossing data used to calculate the NSRT values.
NSRT Result Sets
For each NSRT request, three result sets are returned, NSRT, CYCLES and CROSSINGS.
This set of values includes the nationwide average fatality rate, the average injury rate and the Nationwide Significant Risk Threshold (NSRT) calculated over all accidents and crossings for a selected 5-year period.
Accident prediction values for crossings are calculated each month for 5 preceding years of data. The start and end dates for each cycle charge each month. The CYCLES result set lists the start and end dates for the accident data counts in the crossings result set.
The CROSSINGS result set includes basic data about a crossing's physical and operating characteristics and five years of accident history data gathered for a specific set of dates. The following values are included for each crossing.
· GLOBALRANK: Crossings are listed in order and ranked with the highest collision prediction value first.
· RANK: A crossing data request may include filters to specify which records are returned. A rank for each crossing is established for the subset of records returned in a filtered search.
· PREDCOLLS: The accident prediction value is the probability that a collision between a train and a highway vehicle will occur at the crossing in a year.
· CROSSING: The unique sight specific identifying DOT/AAR Crossing Inventory Number.
· RR:The alphabetic abbreviation for the railroad name.
· FIPS: The five-digit code identifying a county and state
· STATE:The abbreviation for the state where the crossing is located.
· COUNTY:The county where the crossing is located.
· CITY:The city in (or near) which the crossing is located.
· ROAD: The name of the road, street, or highway (if provided) where the crossing is located.
· DATECHANGED: The date of the latest change of the warning device category at the crossing which impacts the collision prediction calculation, e.g., a change from crossbucks to flashing lights, or flashing lights to gates. The accident prediction calculation utilizes three different formulas, on each for (1) passive devices, (2) flashing lights only, and (3) flashing lights with gates. When a date is shown, the collision history prior to the indicated year-month is not included in calculating the accident prediction value.
· WD: The type of warning device shown on the current Inventory record for the crossing where: FQ=Four Quad Gates; GT = All Other Gates; FL = Flashing lights; HS = Wigwags, Highway Signals, Bells, or Other Activated; SP = Special Protection (e.g., a flagman); SS = Stop Signs; XB = Crossbucks; OS = Other Signs or Signals; NO = No Signs or Signals.
· TOTTRN:Number of total trains per day.
· TOTTRK: Total number of railroad tracks between the warning devices at the crossing.
· TTBLSPD: The maximum timetable (allowable) speed for trains through the crossing.
· HWYPVD:Is the highway paved on both sides of the crossing?
· HWYLNS: The number of highway traffic lanes crossing the tracks at the crossing.
· AADT : The Average Annual Daily Traffic count for highway vehicles using the crossing
· RANGE1VALUE, RANGE2VALUE, RANGE3VALUE, RANGE4VALUE, RANGE5VALUE: The count of accidents for the crossing during the period indicated in the corresponding CYCLES listing.
Filtering the crossing data
A list of accident data for all crossings is a very large result set. The NSRT API allows filters to be applied to the request to narrow the selection of data to those crossings important to the user.
· Filters are not required for a request.
· If more than one filter is used only records which satisfy all filters will be selected. This may result in an empty data set if the filter requests are conflicting.
· Multiple filters may be needed to refine a search. For example, there is an ‘ANDERSON’ county in five states. To get the results only for ANDERSON, KS, a state filter must be included.
· Filters which specify a crossing will return at most one record.
· Any combination of submitted filter types is allowed.
· Filter values are not case sensitive
· There is no required order for the filters in the request
The following filter options are available.
End month and year of a prediction data set
The user may review current or historical accident data by indicating the year and month when a set of data was collected. Both values must be submitted, and both must be associated with a stored collection of data. If it is not possible to return a set of data for the indicated dates, the most current collected data is returned. The cycles result set will show which set of data has been returned.
State – Two letter state abbreviation
County – County name, spaces are allowed
RR – Organization code of the Railroad
Crossing – Seven-character crossing number
FIPS – 5-digit FIPS code for a county