People Saving People National Center for Statistics & Analysis Reporting Thresholds Source: SDS data, A Comparative Analysis of Reporting Thresholds Using the NHTSA State Data System Gary Rinehart ALCOSYS, Inc. Crystal Gateway 3, Ste Jefferson Davis HWY Arlington, VA

People Saving People National Center for Statistics & Analysis Reporting Thresholds Source: SDS data, Outline  The NHTSA State Data System (SDS)  Crash Definitions  Purpose of Study  Severity of SDS Crashes  Description of Towaway Indicator Variables  Crash Severity Analysis Using Towaway Indicators  Detailed Property Damage Only Crash Analysis Using Selected Variables  Summary

People Saving People National Center for Statistics & Analysis Reporting Thresholds Source: SDS data, SDS

People Saving People National Center for Statistics & Analysis Reporting Thresholds Source: SDS data, NHTSA State Data System n A collection of crash data received directly from the seventeen states participating in the program. NHTSA adheres to strict confidentiality agreements with the participating states. n The data consists of all state-reported crashes. The census data are received annually. n Each state uses a unique data structure. The data are converted into a standard SAS format at the National Center for Statistics and Analysis (NCSA), and used for research purposes. n NCSA plans to expand the program. The goal is to ultimately have all 50 states participate.

People Saving People National Center for Statistics & Analysis Reporting Thresholds Source: SDS data, State Data System  California  Florida  Georgia  Illinois  Indiana  Kansas  Maryland  Michigan  Missouri  New Mexico  North Carolina  Ohio  Pennsylvania  Texas  Utah  Virginia  Washington

People Saving People National Center for Statistics & Analysis Reporting Thresholds Source: SDS data, Definitions  Fatal Crash – A crash in which at least one fatality occurs.  Injury Crash – A crash in which at least one injury, but no fatalities, occurs.  Property Damage Only (PDO) Crash – A crash without fatalities or injuries.  PDO-Towaway – A PDO crash in which at least one vehicle was towed, generally indicative of a severe PDO crash.  PDO – No Towaway – A PDO crash in which no vehicles were towed.  Towaway Criterion – A reporting threshold where only fatal, injury, and PDO-towaway crashes are reported.

People Saving People National Center for Statistics & Analysis Reporting Thresholds Source: SDS data, Purpose of Study Assuming that states adopt a towaway criterion for reportable crashes, this study attempts to answer the following questions: 1. What proportion of crashes will be lost?  A crash severity analysis was conducted using sixteen states and appropriate towaway indicator variables.

People Saving People National Center for Statistics & Analysis Reporting Thresholds Source: SDS data, Purpose of Study (cont.) 2.What changes in the basic composition of the crash data will occur?  Since fatal and injury crash data will not be affected by the towaway criterion, the emphasis of the research was on the change in composition of PDO crashes.

People Saving People National Center for Statistics & Analysis Reporting Thresholds Source: SDS data, Analysis Variables The following variables from six states were used in the analysis:  Urban/Rural Crash  Single/Multiple Vehicle Crash  First Harmful Event  Manner of Collision (Motor Vehicle in Transport Crashes)  Vehicle Type

People Saving People National Center for Statistics & Analysis Reporting Thresholds Source: SDS data, Severity of SDS Crashes

People Saving People National Center for Statistics & Analysis Reporting Thresholds Source: SDS data, Fatal Crashes State: Years of Data Fatal Crashes (thousands) Percentage of All Crashes in State California: Florida: Georgia: Illinois: Indiana: Kansas: Maryland: Michigan: Missouri:

People Saving People National Center for Statistics & Analysis Reporting Thresholds Source: SDS data, Fatal Crashes (cont.) State: Years of Data Fatal Crashes (thousands) Percentage of All Crashes in State New Mexico: N. Carolina: Ohio: Pennsylvania: Texas: Utah: Virginia: Washington:

People Saving People National Center for Statistics & Analysis Reporting Thresholds Source: SDS data, Injury Crashes State: Years of Data Injury Crashes (millions) Percentage of All Crashes in State California: Florida: Georgia: Illinois: Indiana: Kansas: Maryland: Michigan: Missouri:

People Saving People National Center for Statistics & Analysis Reporting Thresholds Source: SDS data, Injury Crashes (cont.) State: Years of Data Injury Crashes (millions) Percentage of All Crashes in State New Mexico: N. Carolina: Ohio: Pennsylvania: Texas: Utah: Virginia: Washington:

People Saving People National Center for Statistics & Analysis Reporting Thresholds Source: SDS data, PDO Crashes State: Years of Data PDO Crashes (millions) Percentage of All Crashes in State California: Florida: Georgia: Illinois: Indiana: Kansas: Maryland: Michigan: Missouri:

People Saving People National Center for Statistics & Analysis Reporting Thresholds Source: SDS data, PDO Crashes (cont.) State: Years of Data PDO Crashes (millions) Percentage of All Crashes in State New Mexico: N. Carolina: Ohio: Pennsylvania: Texas: Utah: Virginia: Washington:

People Saving People National Center for Statistics & Analysis Reporting Thresholds Source: SDS data, Variability in Crash Composition Type Of Crash Percentage Range Fatal Crash 0.3 – 1.1 Injury Crash 22.7 – 63.6 PDO Crash 35.4 – 76.9 The only state with a true towaway criterion, Pennsylvania has the highest percentage of injury crashes and the lowest percentage of PDO crashes.

People Saving People National Center for Statistics & Analysis Reporting Thresholds Source: SDS data, SDS Towing Indicator Variables  Towaway  Damage Severity  Damage Scale

People Saving People National Center for Statistics & Analysis Reporting Thresholds Source: SDS data, Towaway  California  Georgia  Illinois  Indiana  Missouri  North Carolina  Ohio  Pennsylvania

People Saving People National Center for Statistics & Analysis Reporting Thresholds Source: SDS data, Towaway: Typical Variable Values  Towed / Not Drivable  Not Towed / Drivable  Remained at Scene (optional)

People Saving People National Center for Statistics & Analysis Reporting Thresholds Source: SDS data, Damage Severity  Florida  Georgia  Kansas  Maryland  New Mexico  Washington

People Saving People National Center for Statistics & Analysis Reporting Thresholds Source: SDS data, Damage Severity: Typical Variable Values  Destroyed, Totaled (optional)  Disabling Damage: Any damage to a motor vehicle such that either it cannot be driven, or if driven, it would be further damaged.  Functional Damage: Any damage to a motor vehicle that affects its operation or the functioning of its parts, but is not disabling.  Other Vehicle Damage: Any damage to a motor vehicle, which is neither disabling nor interferes with the function of the vehicle (cosmetic).  No Damage.

People Saving People National Center for Statistics & Analysis Reporting Thresholds Source: SDS data, Damage Scale  Michigan  Texas  Virginia (repair cost)

People Saving People National Center for Statistics & Analysis Reporting Thresholds Source: SDS data, TAD Scale: Typical Variable Values 1.Minor damage, less than element value 2. 2.Minor damage, limited to dents and gouges in body sheet metal or trim. 3.Moderate damage, less than element value 4. 4.Moderate damage, considerable crumpling of body sheet metal, little or no distortion of basic structure or frame. (Towaway at this level and above.) 5.Severe damage, crumpled or torn sheet metal, less than element value 6. 6.Damage severe, not total. Sheet metal severely distorted, crumpled or torn. 7.Vehicle totally damaged.

People Saving People National Center for Statistics & Analysis Reporting Thresholds Source: SDS data, Example of TAD 1 People Saving People National Center for Statistics & Analysis Reporting Thresholds Source: SDS data, Michigan Traffic Accident Report, 8/87

People Saving People National Center for Statistics & Analysis Reporting Thresholds Source: SDS data, Example of TAD 4 People Saving People National Center for Statistics & Analysis Reporting Thresholds Source: SDS data, Michigan Traffic Accident Report, 8/87

People Saving People National Center for Statistics & Analysis Reporting Thresholds Source: SDS data, Example of TAD 7 People Saving People National Center for Statistics & Analysis Reporting Thresholds Source: SDS data, Michigan Traffic Accident Report, 8/87

People Saving People National Center for Statistics & Analysis Reporting Thresholds Source: SDS data, Towaway Indicator Variables Using Towaway indicator variables, the Property Damage Only crashes can be divided into three categories:  Towaway  No Towaway  Towaway Status Unknown A revised Crash distribution can then be determined.

People Saving People National Center for Statistics & Analysis Reporting Thresholds Source: SDS data, Crash Severity (sample size 30.3 million) Crash Severity FrequencyPercent Cumulative Percent Fatal Crash 181, Injury Crash 11,614, PDO- Towaway 5,017, PDO-No Towaway 12,838, PDO (Towaway?) 446, Unknown211,

People Saving People National Center for Statistics & Analysis Reporting Thresholds Source: SDS data, Crashes Lost Using a towaway criterion:  Approximately 42% of all crashes would be lost.  Approximately 70% of property damage only crashes would be lost.

People Saving People National Center for Statistics & Analysis Reporting Thresholds Source: SDS data, Contribution by State (sample size 30.3 million) StateYearsSize%StateYearsSize% CA90-994,890, MO90-991,813, FL90-992,212,3997.3NC92-991,797, GA98280,5790.9NM , IL96-991,133,3623.7OH90-993,759, IN90-992,296,8507.6PA90-991,383, KS ,7222.3TX90-993,514, MD ,4793.2VA , MI90-993,898, WA , Utah does not have a towaway indicator variable.

People Saving People National Center for Statistics & Analysis Reporting Thresholds Source: SDS data, Crash Severity by State Type Of Crash CAFLGAILINKS Fatal Crash Injury Crash PDO-Towaway PDO-No Towaway PDO (Towaway?) Unknown Total

People Saving People National Center for Statistics & Analysis Reporting Thresholds Source: SDS data, Crash Severity by State (cont.) Type Of Crash MDMIMONCNM Fatal Crash Injury Crash PDO-Towaway PDO-No Towaway PDO (Towaway?) Unknown Total

People Saving People National Center for Statistics & Analysis Reporting Thresholds Source: SDS data, Crash Severity by State (cont.) Type Of Crash OHPATXVAWA Fatal Crash Injury Crash PDO-Towaway PDO-No Towaway PDO (Towaway) Unknown Total

People Saving People National Center for Statistics & Analysis Reporting Thresholds Source: SDS data, Towaway States?  PA: Data confirms that Pennsylvania does use a towaway criterion; hence the high percentage of injury crashes and the low percentage of PDO crashes.  MD: Although Maryland has a towaway policy, Maryland data appears similar to states without a towaway criterion. At least 28% of crashes do not meet towaway criterion.  FL: Crashes reported by Florida are at the officer’s discretion. Data suggests that Florida’s reporting criterion may approximate a towaway criterion.

People Saving People National Center for Statistics & Analysis Reporting Thresholds Source: SDS data, Crashes Lost Using a Towaway Criterion States Approximate Percentage Lost IN, IL, MI 60% GA, KS, MO, NM, OH 50% CA, NC, TX, VA, WA* 40% *Assuming large percentage of unknowns for Washington are PDO-Not Towaway

People Saving People National Center for Statistics & Analysis Reporting Thresholds Source: SDS data, Analysis of Property Damage Only Crashes Methodology involves comparison of three data sets:  PDO crashes from CA, FL, MO, NC, and OH  PDO-Towaway crashes from CA, FL, MO, NC, and OH  PDO-Towaway crashes from PA

People Saving People National Center for Statistics & Analysis Reporting Thresholds Source: SDS data, Variables Used The composition of each data set was examined using the following variables:  Urban/Rural Crash  Single/Multiple Vehicle Crash  First Harmful Event  Manner of Collision (Motor Vehicle in Transport Crashes)  Vehicle Type

People Saving People National Center for Statistics & Analysis Reporting Thresholds Source: SDS data, State Selection Criteria  Presence of towaway indicator variables over an extended period: CA, FL, MO, OH, PA = CA, FL, MO, OH, PA = NC = NC =  Presence of Rural/Urban and/or Population Group variables.  Presence of First Harmful Event and Manner of Collision variables with categories approximating the Model Minimum Uniform Crash Criteria (MMUCC).  Low percentage of unknowns for analysis variables.

People Saving People National Center for Statistics & Analysis Reporting Thresholds Source: SDS data, Contribution by State (Sample Size 8.5 million) StateFrequencyPercent CA2,818, FL812, MO1,303, NC1,028, OH2,507,

People Saving People National Center for Statistics & Analysis Reporting Thresholds Source: SDS data, Crash Type CA, FL, MO, NC, OH: PDO CA, FL, MO, NC, OH: PDO- TOWAWAY PA: PDO- TOWAWAY Multiple Vehicle Single Vehicle PDO Crashes (CA, FL, MO, NC, OH) – Sample size 8.5 million. PDO-Towaway Crashes (CA, FL, MO, NC, OH) – Sample size 2.7 million. PDO-Towaway Crashes (PA) – Sample size 0.48 million.

People Saving People National Center for Statistics & Analysis Reporting Thresholds Source: SDS data, Population Density PopulationDensity CA, FL, MO, NC, OH: PDO CA, FL, MO, NC, OH: PDO- TOWAWAY PA: PDO- TOWAWAY Urban Rural Unknown PDO Crashes (CA, FL, MO, NC, OH) – Sample size 8.5 million. PDO-Towaway Crashes (CA, FL, MO, NC, OH) – Sample size 2.7 million. PDO-Towaway Crashes (PA) – Sample size 0.48 million.

People Saving People National Center for Statistics & Analysis Reporting Thresholds Source: SDS data, Population Density PopulationDensity Crash Type CA, FL, MO, NC, OH: PDO CA, FL, MO, NC, OH: PDO- TOWAWAY PA: PDO- TOWAWAY Urban Multiple Vehicle Urban Single Vehicle Rural Multiple Vehicle Rural Single Vehicle PDO Crashes (CA, FL, MO, NC, OH) – Sample size 8.5 million. PDO-Towaway Crashes (CA, FL, MO, NC, OH) – Sample size 2.7 million. PDO-Towaway Crashes (PA) – Sample size 0.48 million.

People Saving People National Center for Statistics & Analysis Reporting Thresholds Source: SDS data, First Harmful Event CA, FL, MO, NC, OH: PDO CA, FL, MO, NC, OH: PDO- TOWAWAY PA: PDO- TOWAWAY Motor Vehicle In Transport Fixed Object Animal Parked Motor Vehicle Pedalcyclist Pedestrian PDO Crashes (CA, FL, MO, NC, OH) – Sample size 8.5 million. PDO-Towaway Crashes (CA, FL, MO, NC, OH) – Sample size 2.7 million. PDO-Towaway Crashes (PA) – Sample size 0.48 million.

People Saving People National Center for Statistics & Analysis Reporting Thresholds Source: SDS data, First Harmful Event (cont.) First Harmful Event CA, FL, MO, NC, OH: PDO CA, FL, MO, NC, OH: PDO- TOWAWAY PA: PDO- TOWAWAY Train Moving Object Rollover OtherNon-collision Unknown PDO Crashes (CA, FL, MO, NC, OH) – Sample size 8.5 million. PDO-Towaway Crashes (CA, FL, MO, NC, OH) – Sample size 2.7 million. PDO-Towaway Crashes (PA) – Sample size 0.48 million.

People Saving People National Center for Statistics & Analysis Reporting Thresholds Source: SDS data, Manner of Collision (Motor Vehicle in Transport) Collision Type CA, FL, MO, NC, OH: PDO CA, FL, MO, NC, OH: PDO- TOWAWAY PA: PDO- TOWAWAY Angle / Turning Head On Rear End Sideswipe Other / Unknown PDO Crashes (CA, FL, MO, NC, OH) – Sample size 5.6 million. PDO-Towaway Crashes (CA, FL, MO, NC, OH) – Sample size 1.5 million. PDO-Towaway Crashes (PA) – Sample size 0.25 million.

People Saving People National Center for Statistics & Analysis Reporting Thresholds Source: SDS data, PDO Vehicle Distribution: CA, FL, MO, NC, OH Vehicle Type FrequencyPercent Passenger Car 10,807, Light Truck 3,473, Large Truck 669, Motorcycle34, Bus105, Other678, Sample size 15.8 million vehicles.

People Saving People National Center for Statistics & Analysis Reporting Thresholds Source: SDS data, PDO-Towaway Vehicle Distribution: CA, FL, MO, NC, OH Vehicle Type FrequencyPercent Passenger Car 3,370, Light Truck 1,057, Large Truck 181, Motorcycle9, Bus16, Other88, Sample size 4.7 million vehicles.

People Saving People National Center for Statistics & Analysis Reporting Thresholds Source: SDS data, PDO-Towaway Vehicle Distribution: PA Vehicle Type FrequencyPercent Passenger Car 534, Light Truck 190, Large Truck 30, Motorcycle1, Bus2, Other4, Sample size 0.77 million vehicles.

People Saving People National Center for Statistics & Analysis Reporting Thresholds Source: SDS data, Vehicle Type Comparison Vehicle Type CA, FL, MO, NC, OH: PDO CA, FL, MO, NC, OH: PDO- TOWAWAY PA: PDO- TOWAWAY Passenger Car Light Truck Large Truck Motorcycle Bus Other PDO Crashes (CA, FL, MO, NC, OH) – Sample size 15.8 million. PDO-Towaway Crashes (CA, FL, MO, NC, OH) – Sample size 4.7 million. PDO-Towaway Crashes (PA) – Sample size 0.77 million.

People Saving People National Center for Statistics & Analysis Reporting Thresholds Source: SDS data, Percent Vehicles Retained PDO-Towaway (CA, FL, MO, NC, OH) Vehicle Type Percentage Retained Passenger Car 31.2 Light Truck 30.4 Large Truck 27.1 Motorcycle29.0 Bus15.6 Other13.1 Percentage Retained = Number of Vehicles (PDO-Towaway)  Number of Vehicles (PDO)

People Saving People National Center for Statistics & Analysis Reporting Thresholds Source: SDS data, Changes in Vehicle Type PDO-Towaway (CA, FL, MO, NC, OH)  Small increase in the proportion of passenger cars and light trucks.  Small decrease in the proportion of large trucks and motorcycles.  Moderate decrease in proportion of buses and other vehicles (motor homes, farm/construction equipment, police/emergency vehicles, etc.).

People Saving People National Center for Statistics & Analysis Reporting Thresholds Source: SDS data, Summary Using the NHTSA State Data System, adoption of a towaway criterion would have the following effects:  A significant decrease in the total number of reportable crashes.  The data shows that at least 42% of the reportable crashes would be lost.  The data shows that at least 70% of the reportable PDO crashes would be lost.

People Saving People National Center for Statistics & Analysis Reporting Thresholds Source: SDS data, Summary (cont.) Low severity PDO crashes would be lost, changing the composition of the remaining PDO crashes as follows:  The proportion of Urban crashes decreases.  The proportion of Single Vehicle crashes increases, with an increase in Fixed Object, Rollover, and Other Non-Collision crashes.  The proportion of Multiple Vehicle crashes decreases, both for Motor Vehicle in Transport and Parked Motor Vehicle crashes.  The proportions of Angle and Head-on collisions increase, while Rear End and Sideswipe collisions decrease.  The proportions of Passenger Cars and Light Trucks increase slightly, Large Trucks and Motorcycles decrease slightly, and Buses and Other Vehicles exhibit a moderate decrease.

People Saving People National Center for Statistics & Analysis Reporting Thresholds Source: SDS data, Questions or Comments? Questions/Comments can be sent to: