# Presentation: 231606

## What we Know about Impaired Driving – NHTSA Overview 

**Rajesh Subramanian**
**Mathematical Analysis Division**
**National Center for Statistics and Analysis, NHTSA**

## Data Source

- Fatality Analysis Reporting System (FARS)
- A census of all fatal motor vehicle traffic crashes in the United States
- Data back to 1982

## Data Needs

- Agency Grant Programs.
- Impaired Driving Countermeasure design.
- Media, Advocacy Groups, Auto Industry.
- Human-centered research.

## Alcohol Data in FARS

- Blood Alcohol Concentration (BAC) values.
- Reported for every Driver and non-occupant (pedestrians, etc.) involved in a fatal crash.
- Surviving Persons – Breathalyzer Tests, PBTs
- Fatally Injured Persons – ME, Coroner Tests.

## Missing BAC Data

- More than half the cases do not have BAC.
- Varies widely across states (10% - 90%).
- Need consistent data to assess trends, etc.
- Reliably Estimate Missing BAC.

## Definitions

- BAC : Blood Alcohol Concentration (g/dl)
- Alcohol-Related Fatalities : Fatalities that occur in crashes involving at least one driver or non-occupant with BAC=0.01+
- Non-occupant: Pedestrian or pedal-cyclist

## Fatalities/Fatal Crashes by Highest BAC Level in Crash,2004

| 

Crashes/
Fatalities | Highest BAC Level in Crash |  |  |  |  |  |  |  |
| --- | --- | --- | --- | --- | --- | --- | --- | --- |
|  | Not Alcohol-Related |  | Alcohol-Related |  |  |  |  |  |
|  | BAC=0.0 |  | BAC=0.01-0.07 |  | BAC=0.08+ |  | BAC=0.01+ |  |
|  | Number | Percent | Number | Percent | Number | Percent | Number | Percent |
| Crashes | 23,285 | 61% | 2,016 | 5% | 12,952 | 34% | 14,968 | 39% |
| Fatalities | 25,942 | 61% | 2,285 | 5% | 14,409 | 34% | 16,694 | 39% |

## A Crash is alcohol-related if...

- One or more drivers in crash have BAC > 0.
- One or more non-occupants in crash have BAC > 0.
- One or more drivers as well as a non-occupant in same crash have BAC >0.

## Alcohol-Related Crashes by Role of Person with Alcohol

## Alcohol Related Fatalities by Role,2004 

**Alcohol Related Fatalities by Role,2004 **

## Alcohol Related Fatalities by Role,2004 

| Role | Number | Percent |
| --- | --- | --- |
| Driver with Alcohol | 8,199 | 49.1% |
| Passenger Riding w/Driver with Alcohol | 2,763 | 16.6% |
| Motorcycle Operator with Alcohol | 986 | 7.6% |
| Motorcycle Rider w/Operator with Alcohol | 646 | 0.7% |
| Non-occupant with Alcohol | 1,969 | 11.8% |
| Driver with no Alcohol | 515 | 5.9% |
| Passenger Riding w/Driver with no Alcohol | 1,264 | 3.9% |
| Motorcycle Operator with no Alcohol | 156 | 0.9% |
| Motorcycle Rider w/Operator with no Alcohol | 118 | 0.1% |
| Non-occupant with no Alcohol | 21 | 3.1% |
| Others | 57 | 0.3% |
| Total | 16,694 | 100.0% |

**Alcohol Related Fatalities by Role,2004**** **

## Alcohol-Related Fatalities by Gender, Role and Age 

## Alcohol-related (AR) fatalities by role and age as a percent of all AR-fatalities in age-group 

**Alcohol-related (AR) fatalities by role and age as a percent of all AR-fatalities in age-group **

## Alcohol Related Fatalities by Role and Gender (25-44 Yr Olds),2004 

**Alcohol Related Fatalities by Role and Gender (25-44 Yr Olds),2004 **

- Males

- Females

## Alcohol Related Fatalities by Role and Gender (25-44 Year Olds),2004 

| Role | Males |  | Females |  |
| --- | --- | --- | --- | --- |
|  | Number | Percent | Number | Percent |
| Driver with Alcohol | 2,966 | 55% | 647 | 46% |
| Passenger Riding w/Driver with Alcohol | 612 | 11% | 270 | 19% |
| Motorcycle Operator with Alcohol | 672 | 13% | 19 | 1% |
| Motorcycle Rider w/Operator with Alcohol | 5 | 0% | 51 | 4% |
| Non-occupant with Alcohol | 659 | 12% | 171 | 12% |
| Driver with no Alcohol | 210 | 4% | 108 | 8% |
| Passenger Riding w/Driver with no Alcohol | 66 | 1% | 81 | 6% |
| Motorcycle Operator with no Alcohol | 68 | 1% | 5 | 0% |
| Other | 121 | 2% | 66 | 5% |
| Total Alcohol Related | 5,379 | 100% | 1,416 | 100% |
| Total Not Alcohol Related | 4,341 | - | 2,101 | - |
| Total | 9,720 | - | 3,517 | - |

## Age of Driver by Age of Fatally Injured Passengers 

## Age of Driver by Age of Fatally Injured Passengers riding with a driver with alcohol

| D       P | 8-15 | 16-20 | 21-24 | 25-34 | 35-44 | 45-64 | 65+ |
| --- | --- | --- | --- | --- | --- | --- | --- |
| 8-15 | 10
[48%] | 7
[32%] | 0
[-] | 0
[-] | 1
[6%] | 0
[-] | 0
[-] |
| 16-20 | 72
[10%] | 450
[63%] | 106
[15%] | 42
[6%] | 20
[6%] | 10
[1%] | 2
[0%] |
| 21-24 | 24
[3%] | 180
[25%] | 268
[37%] | 176
[24%] | 41
[6%] | 19
[3%] | 3
[0%] |
| 25-34 | 26
[4%] | 58
[9%] | 133
[20%] | 252
[37%] | 99
[15%] | 55
[8%] | 8
[1%] |
| 35-44 | 27
[7%] | 23
[6%] | 20
[5%] | 76
[19%] | 150
[37%] | 71
[18%] | 16
[4%] |
| 45-64 | 9
[3%] | 11
[4%] | 8
[3%] | 30
[11%] | 66
[24%] | 109
[40%] | 34
[13%] |
| 65+ | 0
[-] | 0
[-] | 0
[-] | 2
[4%] | 2
[3%] | 15
[29%] | 31
[60%] |

## Alcohol-Related Fatalities when a non-Driver is the only person(s) with alcohol 

## Fatalities in crashes where at least one of Motorcycle Operators had alcohol 

| Role | Number | Percent |
| --- | --- | --- |
| Driver with Alcohol | 1 | 0% |
| Motorcycle Operator with Alcohol | 1,264 | 89.5% |
| Motorcycle Rider w/Operator with Alcohol | 118 | 8.4% |
| Non-occupant with Alcohol | 1 | 0% |
| Driver with no Alcohol | 4 | 0.3% |
| Passenger Riding w/Driver with no Alcohol | 5 | 0.4% |
| Motorcycle Operator with no Alcohol | 13 | 0.9% |
| Motorcycle Rider w/Operator with no Alcohol | 2 | 0.1% |
| Non-occupant with no Alcohol | 5 | 0.4% |
| Total | 1,412 | 100.0% |

**Fatalities in crashes where at least one of Motorcycle Operators had alcohol **

## Fatalities in crashes where at least one of the non-occupants had alcohol 

| Role | Number | Percent |
| --- | --- | --- |
| Driver with Alcohol | 6 | 0.3% |
| Passenger Riding w/Driver with Alcohol | 3 | 0.1% |
| Motorcycle Operator with Alcohol | 3 | 0.1% |
| Motorcycle Rider w/Operator with Alcohol | 1 | 0% |
| Non-occupant with Alcohol | 1,969 | 95.0% |
| Driver with no Alcohol | 8 | 0.4% |
| Passenger Riding w/Driver with no Alcohol | 5 | 0.2% |
| Motorcycle Operator with no Alcohol | 3 | 0.1% |
| Motorcycle Rider w/Operator with no Alcohol | 2 | 0.1% |
| Non-occupant with no Alcohol | 73 | 3.5% |
| Others | 4 | 0.2% |
| Total | 2,073 | 100.0% |

**Fatalities in crashes where at least one of the non-occupants had alcohol **

## Alcohol-Related Fatalities: Trends, Exposure Measures, Rates and Regional Rates 

## Exposure Measures

- No reliable nationwide exposure measure for Impaired Driving.
- Vehicle Miles of Travel (VMT) is the best proxy.
- VMT Data is available by state going back to 1982.
- Rates of Impaired Driving can be generated back to 1982.

## Alcohol Related Fatalities and Fatality Rates, by Year 

**Source:  FARS**

## Alcohol-Related Fatality Rates by State

- U.S. Rate=0.59

## Other Data 

## Median BAC Values

** ****Which means more than ****half**** of all alcohol-involved drivers and motorcycle operators had BACs higher than ****twice**** the legal limit in most states.**

**Median BAC Values**

## Alcohol-Involved Drivers and Motorcycle Operators in Fatal Crashes with Positive BACs (BAC>0), 2004

**Source:  FARS**

**Notes:**
New method offers a continuous distribution of BAC along the entire scale of plausible BAC values.  Equips researchers with ability to 
perform analyses on effectiveness of changing BAC laws from one threshold to another.

## Repeat DWI Offenders

**intoxicated driver(s) and motorcycle **
**operators who had at least one previous **
**DWI conviction**
**--- Accounting for ****7%**** of all alcohol-**
**related fatalities and remained unchanged **
**from 2003****	**

**Repeat**** ****DWI**** ****Offenders**

## Alcohol-Involved Drivers and Motorcycle Operators in Fatal Crashes with Previous Alcohol Convictions

| 
 | Year |  |
| --- | --- | --- |
|  | 2003 | 2004 |
| Drivers* who were Alcohol-Involved and had previous (within 3 years) Alcohol Conviction(s) | 1,111 | 1,039 |
| Percent of All Alcohol-Involved Drivers* | 8% | 7% |
| Number of Fatalities in Crashes in which Drivers* were Alcohol-Involved and had previous Alcohol Conviction(s) | 1,247 | 1,189 |
| Percent of Alcohol-Related Fatalities | 7% | 7% |

*** Includes Motorcycle Operators                                                 Source:  FARS**

## Questions?