Measuring the Chances of DUI Arrest
In a project to measure the probability of getting arrested for
driving under the influence of intoxicants as it relates to blood alcohol
concentration, the Midwest Research Institute of Kansas City, MO, has
explored public awareness about the extent to which DUI laws are enforced. Once discerned, this
information could be useful to increase public awareness, help the police
force in locating drunk drivers, aid in the evaluation of possible DUI
candidates, and help provide quantification of intoxicated drivers on
public roads.
Alcohol Safety Action Projects (ASAP), a workshop funded by the
National Highway Traffic Safety Administration (NHTSA), conducted interviews of thousands of people
in order to ascertain the level of public understanding of DUI law
enforcement. Interviewees were asked several questions, including what
they speculated the possibility was that they may be stopped by the
police after having had several drinks.
Unfortunately, the question does not have an accurate answer,
especially if the intoxication level, or blood alcohol content (BAC), is
not designated. While general ideas of such probabilities do exist,
in-depth research had not been previously carried out on this topic.
Estimates from previous reports calculate that for a 10-mile ride with a
BAC above
0.10% the probability of arrest would be about one in 670, while the
Midwest Research Institute states in their recent report that in fact
that chances are about one in 200.
After measuring this probability of a DUI arrest under controlled
conditions of patrolling and traffic counts, then one can also assess how
many drivers would possess a set BAC range. A random survey of volunteer
motorists driving in the same patrol area provided the outcome of BAC in drivers
who were not arrested, while police records gave the BAC distribution of
those who were arrested. Once this probability can be firmly established,
then communities without ASAPs could avoid expensive roadside surveys and
also be convinced of the value of ASAPs in their communities.
This information could greatly assist police patrols with managing DUI
patrols as it would offer a fixed standard to use in ascertaining the
performance of his unit. More importantly, precise calculation of the
probabilities of being arrested for DUI will aid in garnering the trust
and confidence of the public in carrying out future public education
campaigns against drunk driving.
See the entire study from “Injury Prevention Online” (2000;6:158-161),
entitled “Probability of arrest while driving under the influence
of alcohol“.
