Standardized Field Sobriety Tests Research Articles

Sobriety tests for low blood alcohol concentrations

The legal limits of blood alcohol concentration (BAC) for operators of commercial vehicles throughout the United States, and underage drivers in most states, are approximately half the 0.08–0.10% imposed on other drivers. Easily administered measures involving performance and appearance are needed to establish probable cause for requesting breath tests. Several measures showing relationships to blood alcohol were examined for their ability to distinguish BACs under and over 0.04% within the 0.00–0.08% range. Measures of heat loss, pupillary response, balance, complex tasks, and accuracy under speed were studied in controlled experiments with alcohol-dosed subjects. The only reliable index of blood alcohol was horizontal gaze nystagmus (HGN) as administered in the standardized field sobriety test (SFST), using alternative scoring criteria. Although other measures evidenced intra-individual change at low BACs, the magnitude of change was greatly exceeded by inter-individual differences, thwarting their use in detecting drivers with BACs lower than 0.08%. HGN, however, proved as valid in detecting BACs in the 0.04–0.08% range as at the higher levels of the SFST. It is also as valid when administered to a seated subject as one standing, making it of particular benefit in enforcement, where the behavior of low BAC drivers rarely provides probable cause to request that they leave a vehicle to be tested in a standing position.

Drugs driving – standardized field sobriety tests: a survey of police surgeons in Strathclyde

To determine the opinion of police surgeons within Strathclyde Police to the proposed introduction of Standardized Field Sobriety Tests (SFSTs) in the assessment of suspect drivers. 25 police surgeons who attended a full day training programme in respect of 'Drugs and Driving' received a questionnaire relating to the tests. Following analysis of the responses, an identical questionnaire was posted to all 101 registered police surgeons in Strathclyde, resulting in a 45% response and results compared. Of the conference attendees, 54% of doctors were satisfied with the tests, while 46% expressed reservations. Each test was considered separately, however the Walk and Turn Test and the One Leg Stand Test caused the highest levels of concern from at least 50% of the doctors. POSTAL RESPONSES: 52% were satisfied with the tests, however 48% expressed concerns. Again, the Walk and Turn Test and the One Leg Stand Test were by far the tests causing most concern. a significant percentage of police surgeons in Strathclyde have expressed concerns regarding the SFSTs. Irrespective of length of experience and postgraduate qualification, the tests most contentious are the Walk and Turn Test and the One Leg Stand Test.

Development of a standardized boating sobriety test

A sobriety test capable of being administered on boats was developed as an aid in establishing probable cause to request a breath sample of recreational boat operators suspected of being over the legal alcohol limit. In a laboratory phase some 12 candidate measures suitable for use in a boating environment were assessed for their relationship to blood alcohol levels through administration to 32 subjects tested at blood alcohol concentrations (BACs) of 0.00, 0.06 and 0.12%. Four measures showing significant relationships to BAC were then administered by marine police to a sample of 60 recreational boaters found to have BACs ranging from 0.0 to 0.20%. Three measures still showing significant relationships to alcohol were horizontal gaze Nystagmus given in a seated position, reciting the alphabet from A to Z, and clapping hands alternately with palm and back of hand, while counting. Correlation of the measures with BAC, and the ability to distinguish boaters over and under a 0.10% limit were similar to those found over the same BAC range with the standardized field sobriety test (SFST) for motor vehicle operators. Where there is not sufficient cause to request a boat operator to proceed to shore for testing, a standardized boating sobriety test (SBST) making use of the three measures appears to be a suitable replacement for the SFST.

Evaluation of standardized field sobriety tests training in North Carolina

The purpose of this study was to assess the effectiveness of SFST training in North Carolina. Effectiveness was assessed by comparing differences in the following variables before and after training: (1) the officers’ DWI arrest rates, (2) the officers’ DWI conviction rates, and (3) the arrested drivers’ blood alcohol concentration (BAC) levels. Other variables examined included: the officers’ confidence levels in (4) identifying DWI drivers, (5) writing complete and accurate reports about DWI drivers; and (6) testifying clearly and convincingly in court. The results of this study suggest that officers equipped with SFST training are more confident in their abilities to detect DWI offenders, to write a complete and accurate report, and to testify in court clearly and convincingly. Also there is some evidence that these increased abilities correlate with an increase in DWI arrests.

Diagnosis of Alcohol Intoxication: Effectiveness of Cognitive and Neurovestibular Field Sobriety Tests

Tests from an automated performance test battery of cognitive tests and the standardized field sobriety tests (FST) used nationwide by law enforcement officers were administered in three experiments involving graded dosages of alcohol. In the first experiment, subjects were raised to one of four levels of alcohol dosage in four different sessions. In the second experiment, the descending branch of the blood alcohol level (BAL) curve was monitored from .15 BAL, and cognitive and motor performances were assessed by the Automated Performance Test System (APTS) and FST. In the third experiment, the ascending and descending limbs of the alcohol dosage curve were followed. Dose-response relationships were conducted and were statistically significant (p < .001) in all three studies for all but one test when evaluated singly. Using either test battery, composite scores could be employed to index degraded performance from elevated blood alcohol levels. The best single test was gaze nystagmus from the FST battery and the next best was code substitution from the cognitive battery. Taken singly, the individual tests ranged from 66% to 81% in terms of correctly detecting the dichotomous criterion of < 0.10 versus 0.10 BAC and above. These results are discussed in the context of standards setting for driving under the influence (DUI) and the use of behavioral tests to evaluate over-the-counter and prescription drugs.