DWI Enforcement
Paul Lassalle
Houston Police Department
Traffic Division/DWI Task Force
The DWI Problem

Prior to 1994, over half of the nation’s fatal
crashes involve drivers who have been drinking

In 2005, alcohol was involved in 39 percent of
all fatal crashes
Source - NHTSA Traffic Safety Facts
II - 2
National Statistics

Drunk and impaired drivers kill or injure a
person every minute (65 deaths and injuries
each hour)

1986: 24,045 alcohol related crashes 52.2% of
the total

2005: 15,238 alcohol related crashes 38.9% of
the total
Source - NHTSA Traffic Safety Facts
I - 2A
Texas Statistics

Until 2005 Texas led the nation in alcohol
related crashes

1,569 alcohol related fatal crashes

The average BAC for persons arrested in
Texas for DWI was 0.17
10.2% of the nation’s alcohol related fatalities
occurred in Texas

Source - NHTSA Traffic Safety Facts
I - 2B
Alcohol Facts
Alcohol is involved in
approximately 38% of
all fatal crashes, 9% of
reported injury crashes,
and 5% of non injury
crashes
II - 6
Alcohol Facts
These alcohol related
crashes, injuries, and
fatalities cost society at least
$54 billion in lost
productivity, medical costs,
property damage and other
direct expenditures. Over
$7 billion of these costs are
for health care
II - 6
Drivers with a BAC of 0.10 or
above (national statistics)

Random survey of drivers during a one week
period of time. This survey indicated that 12%
had been drinking and that 2% were above 0.10

This same survey indicated that on weekend
nights, 10% had BACs of 0.10 or higher
II - 3
On a Typical Friday or Saturday
Night
1 out of 7 drivers contacted had a BAC of 0.10 or higher
II - 4
The Average DWI Violator…
Commits the offense 80 times
each year
(i.e. once every 4 or 5 nights)
II - 5
General Deterrence
The fear of arrest
II - 7
There is no reason to fear arrest…
Unless there is a real RISK of being arrested
II - 8
Question?
How many DWI violators do we have to arrest to convince
an appreciable amount of the driving public that there is a
real risk of being arrested?
Every Single One!
Supplemental
Question?
Are we presently arresting enough DWI violators in this
state to convince them that there is a real risk of being
caught?
No!
Supplemental
Question?
If the chances of being arrested are one in 2,000, do you
believe that the average DWI violator will fear arrest?
No!
Supplemental
Why is the DWI Arrest-toViolator So Low?

DWI violators vastly outnumber police officers

Officers are not well trained in DWI detection

Officers fail to recognize the DWI violators
Supplemental
Ft. Lauderdale BAC Study
DWI - 22%
Other
violations - 78%
Citations issued to violators later found to have BACs
between 0.10 and 0.20
II - 9
For Every DWI Violator Arrested…
Three others are contacted face-to-face, but are
released without arrest
II - 10
Psychophysical Tests
Methods of examining mental and/or physical
impairment
Divided Attention
… Concentrating on more than one thing at a
time (mental and physical tasks)
Typical Simultaneous Capabilities
Required for Driving








Information processing
Short-term memory
Judgment/decision making
Balance
Quick reactions
Clear vision
Small-muscle control
Coordination of limbs
Simplicity
Is it reasonable to assume that, if sober…
Anyone like the suspect
The Judge
You
The Jurors
…Would “pass” the test.
The Suspect
Horizontal Gaze Nystagmus
The inability of the eyes to maintain fixation on an
object as it is tracked to the side.
Walk and Turn
(Divided Attention Test)


Instruction Stage
Walking Stage
One Leg Stand
(Divided Attention Test)


Instruction Stage
Balance and Counting Stage
1998 San Diego Field Validation
Study Results
Test
% of Accuracy
HGN
88 %
Walk and Turn
79 %
One Leg Stand
83 %
Florida Field Validation Study of
SFST

95% correct arrest decision based on the threetest battery (HGN, W&T, OLS)

Validated the SFSTs at 0.08 BAC and above
DWI Task Forces (Advantages)
Regular Enforcement
 Highly Trained Officers
 Officer has Concern for Problem
 Assist Regular Patrol Personnel
 Available for Fatal Crashes
 Reliable Testimony
 Increased Arrests
 Existence provides increased deterrence

DWI Task Force (Disadvantages)
 Manpower
Requirements
 Increased Hours on the Job
 Burnout
 Training and Equipment
 Complaints
 Funding Sources vs. Needs
Saturation Patrols
No Full Time Staffing Requirements
 Address Problems at the Location
 Short Term (Less Burnout)
 Media and Publicity Easier
 Interagency Operations
 Public Support and Involvement
 Easily Planned and Implemented

Sobriety Checkpoints
Address Problems at the Source
 High Potential for Media Involvement
 Increased Arrests
 Education
 Public Support (85% support in polls)
 No Need to Observe Dangerous Operation
 Scientifically Supported Results

Now you know what we do, what can
you do?
Make every attempt to keep friends and
family from driving after they have been
drinking.
 Always use a designated driver if you will be
out drinking.
 If you see an intoxicated driver, call *DWI.
 Support organizations working on the
problem
