NTL Record

Title Validation of the Standardized Field Sobriety Test Battery at BACs below 0.10 Percent
Record ID 25935
Personal Name
Creator
Stuster, Jack, 1947-; Burns, Marcelline
Source vi, 34 p. : ill.
Corporate Creator Anacapa Sciences, inc.
Corporate
Contributor
United States. Department of Transportation. National Highway Traffic Safety Administration
Publisher United States. National Highway Traffic Safety Administration
Publication Date 19980800
Language English
Abstract This study evaluated the accuracy of the National Highway Traffic Safety Administration's (NHTSA's) Standardized Field Sobriety Test (SFST) battery to assist officers in making arrest decisions for Driving While Intoxicated (DWI) at blood alcohol concentrations (BACs) below 0.10 percent. NHTSA's SFST battery was validated at 0.10 percent BAC in 1981. The trend to reduce statutory DWI limits to 0.08 percent BAC prompted this research project. The research was composed of several project tasks, including planning, site selection, training, data entry, and data analysis, in addition to the actual conduct of a major field study. The City of San Diego, California, was selected as the site. Seven officers of the San Diego Police Department's alcohol enforcement unit were trained in the administration and modified scoring of NHTSA's SFST battery (i.e., Horizontal Gaze Nystagmus-HGN, Walk and Turn, and One Leg Stand). SFST scoring was adjusted: the observation of four HGN clues indicated a BAC >/= 0.08 percent (rather than four clues indicating a BAC >/= 0.10 percent), and the observation of two HGN clues indicated a BAC >/= 0.04 percent. During routine patrols, the participating officers followed study procedures in administering SFSTs and completing a data collection form for each test administered. The officers' final step in each case was the administration of an evidentiary breath alcohol test. Data analysis found the SFSTs to be extremely accurate in discriminating between BACs above and below 0.08 percent. The mean estimated and measured BACs of the 297 motorists tested were 0.117 and 0.122, respectively; the difference between the means (0.005 percent BAC) is very small and operationally irrelevant. Further, analyses found the HGN test to be the most predictive of the three components of the SFST battery (r=0.65), however a higher correlation was obtained when the results of all three tests were combined (r=0.69). Decision analyses found that officers' estimates of whether a motorist's BAC was above or below 0.08 or 0.04 percent were extremely accurate. Estimates at the 0.08 level were accurate in 91 percent of the cases, or as high as 94 percent if explanations for some of the false positives are accepted. Officers' estimates of whether a motorist's BAC was above 0.04 percent but lower than 0.08 percent were accurate in 94 percent of the decisions to arrest and in 80 percent of cases overall. Also, the officers and prosecutors who were interviewed about the SFSTs found the test battery to be acceptable for field use to establish probable cause for DWI arrest. The results of this study provide clear evidence of the validity of the SFST battery to discriminate at 0.08 percent BAC, using a slightly modified scoring procedure. Further, study results strongly suggest that the SFSTs also accurately discriminate at 0.04 percent BAC. /Abstract from report summary page/
Rosap ID dot:1616
Rosap URL https://rosap.ntl.bts.gov/view/dot/1616
TRT Terms Alcohol tests; Accuracy; Blood alcohol levels; Drunk driving; Law enforcement; Traffic arrests; Field studies
General Subjects DWI enforcement
Classification NTL - LAWS AND REGULATIONS - LAWS AND REGULATIONS;
NTL - SAFETY AND SECURITY - Highway Safety
Geographical
Coverage
San Diego (California); United States
TRIS Online
Accession No
764769
Contract Number DTNH22-95-C-05192
Report Number DOT-HS-808-839; NTIS-PB2001102493
Availability NHTSA - Behavioral Safety Research
Resource type Research Paper
URL https://ntlrepository.blob.core.windows.net/lib/25000/25900/25935/DOT-HS-808-839.pdf
Alternative URL http://www.mass.gov/mdaa/mvcrimes/Validation%20of%20SFST%20below%20.10.pdf
Format PDF
Database NTL Digital Repository