If you have issues viewing or accessing this file contact us at NCJRS.gov. \ " ooT"HS,805-864 ..... :. r. !i "~ • " DEVELOPMENTAND FIELD TEST OF PSYCHOPHYSI V. Tharp M. Burns H. Mosko~tz Southern California Research Institute i, 6305 Arizona I~r~ Los Anples, CaJifornia 90045 Contract NOo ~3T-HS-8.01970 Contract Amto $205,579 MARCH 1981 ! FINAL REPORT This document is available to the U.S. public through the National Technical Information Service, • Springfield, Virginia 22161 , Prepor~ for U.So DEPARTMENTOF TRANSPORTATION j.... NalJonal Highway Traffic Safety Adminisb'alion Washington, D.C, 20590 o- /. :a" .~~,:~.~,.~-.~: _,-~. !~ ~ ..... ~.~ ....: • ~ ~ ~ L ~ -~ I~,~ ~I 8~ ~D ... ,, ~ ~ • .~' ~ I~l~ ~.~ .~I~ ____3~._• ............ •~ ,-~ .~ ~..~ ~ ~ ~ | -i|- ~ ~ ~ .~ ~ ~.-'~.~ TECHNICAl REPORT STAND+,,,D <PIT!.E is:.. I. Report He. J 2. Govemmer ~cc+essio, No. 3. Recipient's Catalog No. DOT-HS-805-864 4, .Title end $ublitle + $. Repo,t Dote DEVELOPMENT AND FIELD TEST OF PSYCHOPHYSICAL MA~Ch 1 qR1 ! TESTS FOR DWI ARREST 6. Performing O,0o~ia~tion Cede 7. A.tKo,(,) ~. Por/4)¢~ng Ol@on|Beflon I~epo,, i'de. V. Tharp, M. Burns, and He Moskowitz SCRI-TR81- .+ i 9. Pedo,ml, 0 O+g~llotio, N~o ~d Ad~,oc+ 10. We,& U,~t Me. ~ "Southern California Research Institute • I !. Co,t,oct o, G,ent No. 6305 Arizona Place +~,~ ; • LOS Angeles California 90045 <~< DOT-HS-8-01970 If 13. Type of Repo,t end Pe,iod Co~,er*d ]2. Sponsorlng AgencyName end Add,osl '~i '*'[/.~ Final Repoz~h • I Department of Transportation /i ;Aug._~,1978 -March 1981 National Highway Traffic Safety Admin'istratior l • 14, $ponso,i~gAgoncy Code " . '+ Washington, D. C. 20590 I IS..~,upplementayy Nolo0 none i 16. Abnt,oct " •Administration and scoring procedures Were standardized.for ' i a sobriety test battery consisting of the walk-and-turn test,**.the .+I~ one leg stand test, and horizontal gaze nystagmus. The effectiveness of the standardized battery was then evaluated in the laborat0rY.and, to a limited extent, in the field. Ten police officers administered the tests in the laboratory to 297 drinking volunteers with blood alcohol concentrations (BACs) ranging from 0 to 0o18%o The officers were able to classify 81% •Of` these volunteers, on the basis of their test scores, with respect to whether their BACs were above or below 0o10%. Officer est:imates of the BACs of people they tested differed by 0.03% on the average from the actual BAC. Interrater and test-retest reliabilities for the test battery ranged from 0°60 to 0.800 - ° In a limited field evaluation police officers filled out 3128 data forms, each represented a driver stopped during a three month ' period. Police officers, after training on the administration and scoring procedures for the test battery, tended to increase their arrest rates and appeared to be more effective in estimating BACs of stopped drivers than they were before training. Anonymous breath ~~' 1 testing of released drivers who were stopped indicated that many of the drinking drivers were never given a sobriety test. ' ++ : i 17. Key ~o,d, sobriety test one leg stand This document is available to. the standardization horizontal gaze- U°S. public through the National o alcohol nystagmus Technical Information Service, I police Springfield, Virginia+22161 . Walk and turn "+*++vc°+"+h++uncla++***e onclas+i *+ l" + • + :ors DOT F 17g0.7 co-69) ', ..+ ,. i I - + .'... •.r PREFACE This study involved the participation of three different police agencles whose cooperation and support was essential. We are especially grateful for the exceptional contributions to•the : S project of th e administrative•and patrol personnel of these agencies. The•agencies, along with our principal point of contact, are listed below in alphabetical order. California Highway Patrol, Southern Division Cpt. Kenneth Rude LosAngeles County• Sheriff's Department Sgt. Harry Douglas Los Angeles Police Department, Central Traffic Sgt. Richard Studda~d • • ~ We also wish to acknowledge the contribution Of two research ~ assistants, Melinda Baille and Leslie Rosdol, whose contribution was exceptional. The Contract Technical Managers for t~is project were Stephen Benson, Pamela Anikeeff, and Robert Schweitz. We appreciate their assistance and support. 4 lli TABLE OF CONTENTS PAGE I o INTRODUCTION ooooooo•ooooo °°e°°oeo•o•e•oe•o•ooo•.o.oo 1 Ao PRELIMINARY ASSESSMENT OF FIELD SOBRIETY TESTS.... B. PILOT TESTS WITH THE SELECTED TEST BATTERY '5 ,, 2 1. •Standardization . q 3 2, Field Observation°::: ::::::::::::::::::::::: 3" 3 • Pilot Subjects ooooooo•ooo•••eo~.•e•oooee..,o " 4 ao Walk and Turn Test ................. ... 6 4 b, One Leg Stand Test ............... ...... 5 ............ ...... c. Gaze Nystagmus Test 7 If. LABORATORY EVALUATION OF THE TEST BATTERY 13 / A. LABORATORY PROCEDURES ......................... ..... •33 i• • Police Officers, Observers, and Laboratory • ParticiDants "••°o•eooeoe••••o••o•ooe.e~oo, 13 2. Training Precedures for P01ice 0fficers ..... 16 3• Testing Procedures oo••e•oo••o•eoe•oe 16 a Participants Oo'•e•o•ee~•e&o•e••" ....... 16 bo Officers• and Observers • ......ooeo • ,... 18 .j • ' B. TEST BATTERY VALIDITY e°e•°"oooooe•oo~oe•ooeoe.o'e. "'. i9 ~ . 1% . 1. BAC Estimates .......... 2o Impairment and Arrest Decisions .::':: ........ 19 3. Ability to Classify Subjects with Respect • ~20: to 0.10% BAC ........................ .... -- 20 4. Nystagmus Criteria .................. ........ ". 2•5 a• BAC Versus Angle Onset ............... 25 b. Rater Estimate Versus Machine Estimate of Onset ................. .......... 30 C. RELIABILITY --Qoooooeelooooo • 30 lo Interaction Reliability ....... " '~ " " ...... : " " - 3!0 J 2. Test-Retest Reliability " - 34 : I II. FIELD EVALUATION PRECEDURES .................. 37 , " :. .~ , " . , ~- ' . , A le POLICE AGENCY @ o • o • • • • o o • o o o e o o e e o "'" ...... 37 _ .....7 L -" Y i Ac~u~s~7~o~s ' • ',." ~ , ,, , . - ,. ,- PAGE 38 ~ ~£ation c 3~ 38 °•°°°°°++&°o*bo+~+%+o'ee +~o°®e+°=.* 38 ~ sTuDY DESIGN 39 ++ +~+++tNG POLICE OFFICERS °°°~'&oomo.mgoo~eg.,oomo o 41 +°D+ +++LmC+tOm ++ . l++lO~++OOmlOOO++.~'O~+m++++.O+Ir++lm 42 t.+'.~ ba+a F~-ms +ooooooo+ooemb.++&oo~oa+o%.++++.+ ~2 2+ Ridealong Data ° .... +°+o+o+o+ .... +o.°°°+ .... r 45 .!++9+ +~O~TtS OP THE FXmLD STUDY eo • +oLeo•••eeL. ~0 +~NATOREQF T~+ STOPEE POPULA+T+ON +o + +° " "om%e D~ o• o 5O i Age • o oeooo~-ooloooe.osoea~oooo.o m ~2 2~• Sex ..... ..... ..... "'+" + ma+c+ +'+'''r"',++'~+++''°++~ +++'.'"+'0++" 52 + °+°+°°°°°'°° ++°o +*•+•'co+ + 52 +B•% ++m++~+ BAKERY EFFECTIVENESS .... °oooo~o..oeo+oo%,o.0.e.~o. Qo 54 ~I+ Wil*l the Percentages of ~he S%opees ~Pn+ ,Are Arrested Increase after the Training on +the Test Battery? 6°ooee +2'~ Will +Police Officers Make More Accurate 55 •Decision with Respect to a +~AC of 0,o10% after iBeing Trained on the Test Battery? .o 57 +a. ~xposure to Drinking DrriVers +,.oo+.oo.+ 57 b. AcCuracy of Decisions o.~..o..+ .... .+o...o 57 3 ~, [Wi+l~ the Mean BAC of Arrested Drfvers Be +Reduced after hhe Test aattery +Is ~nt+rbduced? o o . +..+ooo+o+ °++. + +~60 + o o *+62 Refusals. o0oo°'ooo0ooooo~oo~°o~ oo- eo+•oo 62 +~. Will ~Police Officers More [accurately Est'~ma+te the BAC Levels of st opees M~+t~r Being Trained on the Test ~attery?, °~°+°°•°°°°°m°°o~o~oo+o+ • °oooemeoeoe°.oe' ~62 + Few Stop ~re ~eS~ o ........ o+.°° a+ ees 162 b. Most Officers'BAC~Est.ima~eS Were Inva lid +.o++ooo++++.+•........... ++. Co ~lood and Urine Da~a+Were 0bta+~ned on a Biased Sample of Arzes~ees ...+ 163 ~d. Given ~hese Problems ~ the ~Accuracy of the Officers ~ BAC Estimates Tended To Be More Accurate after Training' • ° ° e e • o • ° • ~ o'~'o o o" • • - ~L •L+ P J PAG~ 5. BAC Distribution of Police Stopees .......... ... 65 a. Driver's BAC Versus His Arrest Probability.. 65 b• BAC During Different Phases of the Study.... 65 1 c. BAC Versus Type of Driving Error ........ .... 68 C. FEASIBILITY ................................... , ....... 68 i. Police Attitude Toward DWI Arrests ............. 68 2. Police Acceptance of Standard Administration and Scoring Procedures QIe°''o•o•e•eeoeeooe•oee• 3 Set BAC Levels 69 md • • oeeoeooeooomooeooeoooooeeeeoo.eee 70. V. CONCLUSIONS AND RECOMMENDATIONS • °eoo 0oooo. • oooooo° oeoo... 72 A. CONCLUSIONS O'°Ooo@°°oeooooooooeoooooeeoooo@eeeaooeeo 72 B. RECOMMENDATIONS ...................................... - 73 1. Police Attitude and Motivation 73 2. Adequate Time Frame for Data Collection ......... 73 3. Other Considerations .... "''" °°°e'eO•eeooee.ooee•eeeeeeeo 74. IV. REFERENCES •O@°"••@gOQtg•qleeemOoQoeme~oooo~oe4eooeeeeoeee 75 APPENDIX A: LITERATURE REVIEW •°eeDeeeooe~eeooeeeeeeeee.e 79 A. ALCOHOL AND NYSTAGMUS ........... 79' l• Vestibular Mechanism ...................... -.-o- 79 .2° .... Neural Mechanism °•°'••°•e-oeooeoeeoeuooe..°ele.' 81 3. Gaze Nystagmus ................. • ................ 82 B o ALCOHOL AND BALANCE °eeeeeeeoeee.eee.oeeooool o, ! 83 1. Walk the Line .................................. 84 2. One Leg Stand °l°°eeoooeooooooeeoooooteoeoo~eooo, dp • 8•4 APPENDIX B: INSTRUCTIONS AND SCORING SHEET • ooeooeeoooe • . 85 .J 1• vii i • C. • " ).: " , •. .... o LIST "OF TABLES TABLE PAGE i. Backround of Officers Who Scored and Administered the Field Sobriety Test Battery.. 12 2~ Age and Sex Comparison of Laboratory participants with Stopees from the Field Evaluation .............................. 14 3° Mean Absolute Value of the Difference Between the Actual BAC and the Estimated BAC of Each Rater .... ....................... 21 p 4. Percentage of Subjects Classified as "Arrested" or "Impaired"'