Table 3: Comparison of Model Results using Mean Absolute Deviation for Hazardous Liquid Pipelines,,,,
Model,Description,MAD,,
Naïve model,Previous year’s incident count,1.0,,
Mileage alone,Modeled with negative binomial,1.0,,
PIPP rank ,As presently used by PHMSA,7.6,,
PIPP total score ,Modeled with negative binomial,2.0,,
PIPP input variables,Modeled with negative binomial,1.1,,
PIPP output variables (L-scores) ,Used to calculate PIPP components and modeled with negative binomial,3.2,,
Inherent risk – using pipeline data ,Infrastructure variables from annual reports and modeled with negative binomial,1.0,,
Performance risk – using inspection data about operators,Inspection results from IM inspections,1.5,,
Historical risk – using incident data,"Number of past three year’s incidents, modeled with orthogonal regression",1.1,,
"SOURCE: U.S. Department of Transportation, Research and Innovative Technology Administration, Bureau of Transportation Statistics, http://www.bts.gov",,,,