SafeStat
Safety Status
Measurement System
(Version 8.6)
What is SafeStat?
- SafeStat is a data-driven analysis system that
determines the current relative safety status of individual motor
carriers.
- SafeStat was developed at the Volpe Center for the Federal
Motor Carrier Safety Administration (FMCSA).
- Data used are maintained and managed at the Federal level
by the FMCSA.
Uses
of SafeStat
·
FMCSA Compliance Reviews
(CRs):
o Semiannually identifies and
prioritizes carriers for on-site FMCSA compliance reviews.
·
PRISM
Program:
o Identifies and monitors
poorly performing carriers for the PRISM Federal/State safety improvement
process (MCSIP).
·
Inspection
Selection System (ISS):
o Supports recommendation of
evaluated carriers’ drivers and vehicles for roadside inspections.
o Makes SafeStat results
available via the Internet to industry and the public to promote safety
awareness and self-improvement.
SafeStat Methodology
- Involves
analytically assessing a motor carrier in four Safety Evaluation
Areas (SEAs):
- Accident SEA
- Driver
SEA
- Vehicle
SEA
- Safety
Management SEA
- Each
SEA is based on two or more indicators supported by
different data sources.
SafeStat Design
- Event and exposure data are
used to calculate normalized measures for each carrier
- Measures are ranked and assigned
percentile values (Indicators) from 0-100 - with 100 being highest or
worst
- Indicators are combined into SEA
values
- SEA
values are weighted and summed to derive the SafeStat
score.
SafeStat Hierarchy and Features
- The SafeStat algorithm design is
computationally hierarchical beginning with safety event
data building to a SafeStat Score.
- Algorithm features data sufficiency tests,
normalization and weighting.
Description of
Hierarchy and Features Pyramid:
Base Level:
Carrier Descriptive Data
Level Two:
Safety Event Data
Level Three:
Safety Measures
Level Four:
Indicators
Level Five:
SEA Values
Top Level:
SafeStat Score
SafeStat Overview Pyramid:
Base Level: Data
Sources by Carrier
·
State Reported & FMCSA Collected Truck
Crashes
·
Moving Violations
·
Out-of-Service Violations from Roadside
Inspections
·
Violations from onsite Compliance Reviews
·
Closed Enforcement Cases
Level Two:
Measures
Level Three:
Indicators
Level Four:
Accident SEA, Driver
SEA, Vehicle SEA,
Safety Management SEA
Top Level:
Motor Carrier SafeStat Score
SafeStat Data
At the foundation of SafeStat are safety event data and exposure
data.
- Carrier specific safety event
data reflect the carrier’s safety compliance and performance and include:
- State Reported Crashes (last 30 mos.)
- Recordable Crashes from CRs (last 12 mos. CRs)
- Roadside Inspection Violations (last 30 mos.)
- Moving Volations (last 30 mos.)
- Compliance Review Violations (last 18 mos. CRs)
- Closed Enforcement Cases (last 6 years)
- Exposure data normalize a carrier’s safety
event data:
- Number of drivers/vehicles and VMT
- Number of inspections
SafeStat Measures
- Safety measures are the
result of normalizing safety event data.
- Example: accident event
data are converted to accident rates, which
take into account differences in exposure.
SafeStat Indicators
- Indicators rank carriers by their safety measures converted to a percentile (0-100) scale.
- When determining indicators,
SafeStat may employ peer groupings that reflect differences in operations to
assure appropriate comparisons among carrier types and size classes.
SafeStat SEA Values
- Safety Evaluation Areas (SEAs) represent the four major criteria used to evaluate
carriers’ safety status.
- A SEA Value, also on a 0-100,
percentile scale, is derived from the Indicators
related to that SEA.
- For example a SEA Value of 85 means:
o 85% of the carriers (that have sufficient data) have a better
safety status in that SEA
o 15% have a worse safety status
SafeStat SEAs
·
Accident
·
Driver
·
Vehicle
·
Safety Management
Accident SEA Summary
Base Level:
- State-Reported Crash Data and Census Data
- Compliance Review Data
Level Two:
- Accident Involvement Measure (AIM)
- Recordable Accident Rate (RAR)
Level Three:
- Accident Involvement Indicator (AII)
- Recordable Accident Indicator (RAI)
Top Level: Accident SEA
Accident SEA
Data & Measures:
- State reported crashes (using NGA standard) over past 30
months normalized by # of power units from FMCSA carrier registration data
yield the Accident Involvement Measure (AIM).
- Recordable crashes from Compliance Reviews (CRs)
conducted during the previous 12 months normalized by vehicle miles traveled
(VMT) yield the Recordable Accident Rate (RAR) Measure.
Accident SEA Accident Involvement Indicator (AII)
Base Level:
State-Reported Crash Data and Census Data
Level Two:
Accident Involvement Measure (AIM)
Level Three:
Accident Involvement Indicator (AII)
Top Level:
Accident SEA
- Accident Involvement Measure
(AIM) applies time weighting (most recent crashes have greatest weight) and
severity weighting (crashes involving injury/fatality and/or HM release have
more weight).
- AIM is calculated
by dividing weighted-crashes by average # of power units.
- AII is percentile ranking of weighted AIM.
- Carriers are peer-grouped by similar # of crashes and
ranked on a percentile basis to obtain an AII.
Accident SEA - Recordable Accident Indicator (RAI)
Base Level:
Compliance Review Data
Level Two:
Recordable Accident Rate (RAR)
Level Three:
Recordable Accident Indicator (RAI)
Top Level:
Accident SEA
- # of Recordable Crashes and last 12 months VMT data are
gathered during CR.
- Recordable crashes are divided by VMT and multiplied by 1
million to obtain a Recordable Accident Rate (RAR) per million miles
traveled.
- Carriers are peer-grouped by similar # of crashes and
then ranked on a percentile basis to obtain the RAI.
Accident SEA Value Calculation
Level Three: Accident
Involvement Indicator (AII)
Level
Three: Recordable Accident
Indicator (RAI)
Top
Level: Accident SEA
Value
- For Carriers with no CR within past 12 months:
- Carriers with CR within past 12 months and no
state-reported crashes since the CR
- Carriers with CR within past 12 months and at least one
state-reported crash since the Compliance Review:
- Accident SEA = highest of (AII, RAI)
Driver SEA Summary
Base Level:
- Driver Roadside Inspections
- Compliance Review Data
- Moving Violation Data from Roadside Inspections
Level Two:
- Driver Inspections Measure (DIM)
- Driver Review Measure (DRM)
- Moving Violations Measure (MVM)
Level Three:
- Driver Inspections Indicator (DII)
- Driver Review Indicator (DRI)
- Moving Violations Indicator (MVI)
Top Level: Driver SEA
Driver SEA
Data and Measures:
- Driver OOS Violations normalized by number of roadside inspections over past
30 months yield the Driver Inspection Measure
(DIM).
- Driver-Related Critical and Acute
Violations from CRs completed within past 18 months yield the Driver Review Measure (DRM).
- Moving Violations over past 30 months normalized by number of drivers
yield the Moving Violation Measure (MVM).
Driver SEA Driver Inspection Indicator (DII)
Base Level: Driver
Roadside Inspections
Level
Two: Driver Inspections Measure
(DIM)
Level Three:
Driver Inspections Indicator (DII)
Top
Level: Driver SEA
- DIM is based on OOS inspections that are
severity-weighted (based on # of DOOS viol.) and time-weighted:
- 0-6 months old # of inspections (3x)
- 7-18 months old # or inspections (2x)
- 19-30 months old # of inspections (1x)
- DIM is adjusted up for violations of OOS orders (aka
jumping OOS orders)
- Carriers are peer-grouped by similar # of driver
inspections
- DII is percentile ranking of DIM
Driver SEA - Driver Review Indicator (DRI)
Base Level: Compliance
Review Data
Level
Two: Driver Review Measure
(DRM)
Level Three: Driver
Review Indicator (DRI)
Top
Level: Driver SEA
- Driver Review Measure (DRM) is based on violations of
driver-related Critical and Acute Regulations from CRs.
- DRM accounts for the number and severity of
violations.
- DRI is percentile ranking of DRM.
- Carriers with CR and no violations are given a DRI of
0.
Driver SEA - Moving Violations Indicator
(MVI)
Base Level: Moving
Violation Data from Roadside Inspections
Level
Two: Moving Violations Measure
(MVM)
Level Three: Moving
Violations Indicator (MVI)
Top
Level: Driver SEA
- MVM is based on Moving Violations (MVs) issued in
conjunction with roadside inspections normalized by the number of drivers.
- Time weighting is applied to violations:
- 0-6 months old # of MVs (3x).
- 7-18 months old # or MVs (2x).
- 19-30 months old # of MVs (1x).
- Carriers are peer-grouped by similar # of MVs.
- MVI is percentile ranking of MVM.
Driver SEA Value Calculation
Level Three:
- Driver Inspections Indicator (DII)
- Driver Review Indicator (DRI)
- Moving Violations Indicator (MVI)
Top Level: Driver SEA Value
- Driver SEA Value is the highest of the DII and DRI and uses the MVI when its
value is greater than the DII and DRI.
- When the MVI is greater than the DII and DRI, Driver SEA
is equal to the weighted average of MVI and the highest of the DII and
DRI.
Vehicle SEA Summary
Base Level:
- Vehicle Roadside Inspections
- Compliance Review Data
Level Two:
- Vehicle Inspections Measure (VIM)
- Vehicle Review Measure (VRM)
Level Three:
- Vehicle Inspections Indicator (VII)
- Vehicle Review Indicator (VRI)
Top Level: Vehicle SEA
Vehicle SEA
Data and Measures:
- Vehicle OOS Violations normalized by number of roadside inspections over past
30 months yield the Vehicle Inspection Measure
(VIM)
- Vehicle-related Critical and Acute
Violations from CRs completed within past 18 months yield the Vehicle Review Measure (VRM)
Vehicle SEA - Indicators VII & VRI
- VII is similar to DII but uses Vehicle OOS violations
instead of Driver OOS violations.
Hierarchy
Base Level:
Vehicle Roadside Inspections
Level Two: Vehicle
Inspections Measure (VIM)
Level Three: Vehicle
Inspections Indicator (VII)
Top Level: Vehicle SEA
- VRI is similar to DRI but uses Vehicle-related violations
of Acute/Critical regulations.
Hierarchy
Base Level:
Compliance Review Data
Level Two: Vehicle Review
Measure (VRM)
Level Three: Vehicle Review Indicator
(VRI)
Top Level: Vehicle SEA
Vehicle SEA Value Calculation
Level Three:
- Vehicle Inspections Indicator (VII)
- Vehicle Review Indicator (VRI)
Top Level: Vehicle SEA Value
Safety Management SEA Summary
Base Level:
- Closed Enforcement Cases
- Compliance Review
Level Two:
- Enforcement Severity Measure (ESM)
- Safety Management Review Measure (SMRM)
- HM Review Measure (HMRM)
Level Three:
- Enforcement History Indicator (EHI)
- Safety Management Review Indicator (SMRI)
- HM Review Indicator (HMRI)
Top Level: Safety Management SEA
Safety Management SEA
Data and Measures:
- Safety Management/HM Critical and
Acute Violations from CRs completed within past 18 months yield the Safety Mgmt Review Measure (SMRM) and the HM Review Measure (HMRM).
- SMRM and HMRM account for the number and severity of
violations.
- Closed Enforcement Cases are used to determine the Enforcement Severity Measure (ESM).
Safety Mgmt SEA - Indicators SMRI & HMRI
Hierarchy
Base Level:
Level Two:
- Safety Management Review Measure (SMRM)
- Safety Management Review Indicator (SMRI)
Level Three:
- HM Review Measure (HMRM)
- HM Review Indicator (HMRI)
Top Level: Safety Management SEA
SMRI is similar to DRI but uses Safety Management-related
violations of Acute/Critical regulations.
- HMRM is similar to DRI but uses Hazardous
Material-related violations of Acute/Critical regulations.
Safety Mgmt SEA - Enforcement History Indicator (EHI)
Hierarchy
Base Level:
Closed Enforcement Cases
Level Two: Enforcement Severity
Measure (ESM)
Level Three: Enforcement History Indicator
(EHI)
Top Level: Safety Management SEA