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AN OVERVIEW OFRANDOM BREATH TESTING
OPERATIONSIN VICTORIA 1989-1991
by
GLENN SULLlV AN
ANTONIETTA CAVALLO
ALAN DRUMMOND
October 1992
Report No. 40
glendaStamp
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MONASH UNIVERSITY ACCIDENT RESEARCH CENTREREPORT DOCUMENTATION PAGE
Report No.40
Report DateOctober 1992
ISBN0732600405
Pages21
Title and sub-title:
An overview of Random Breath Testing Operations in Victoria 1989-1991.
Author(s):
Sullivan, G.Cavallo, A.
Drummond, A.E.
Sponsoring Organisation:
Transport Accident Commission222 Exhibition StreetMelbourne VIC 3000
Abstract:
Type of Report & Period Covered:
GENERAL, 1989-1991
Towards the end of 1989 the Victoria police took deliveryof13 highly visible, purpose-built buses fromwhich to conduct RBT operations. Prior to that testing had been primarily car-based. Operational datafrom the initiative have been made available to monitor the changes in police operations as the initiativeevolved. RBT operational data from July 1989 to June 1991, covering the period where buses wereintroduced, have been used to monitor these changes.
The main change in RBT activity over the two years was the increased usage of buses and the resultantdecrease in car-based testing. In the metropolitan area the change to buses was almost immediate whilethe introduction of buses to rural Victoria was much slower and varied across police districts.
The introduction of buses has led to increases in the number ofRBT tests and gradual, but relativelysmaller, increases in the total number of hours of RBT operations and session duration in themetropolitan area. In the rural areas the number of tests and duration ofRBT sessions have, until early1991, remained relatively constant. The number of hours spent testing in rural areas has varied overtime.
The main change due to the introduction of buses for the purpose ofRBT has been a large increase in
the number of people tested for only small changes in the total time spent testing.
KeyWords:(IRRD except when marked*)
evaluation (assessment), collision,road trauma, enforcement,Blood Alcohol Content, alcohol *,drink driving *, Random Breath Testing*
Disclaimer:
This report is disseminated in the interests ofinformation exchange. The views expressed arethose of the authors, and not necessarily those ofMonash University.
Reproduction of this page is authorised.
AN OVERVIEW OF RANDOM BREATH TESTING OPERATIONS ... 111
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Contents
ACKNOWLEDGEMENTS VII
EXECUTIVE SUMMARy IX
1.0 INTRODUCTION 1
2.0 RBT INITIATIVE - OPERATIONAL DATA 1
2.1 RBT Operations Statewide 1
2.2 RBT in Metropolitan and Rural Victoria 3
2.2.1 Hours of RBT testing 32.2.2 Number of RBT tests 3
2.2.3 Car and bus-based RBT operations .42.2.4 RBT session duration 72.2.5 Start/end times ofRBT sessions 12
2.2.6 RBT by day of week 162.2.7 PBT 172.2.8 Hit rates 17
2.3 RBT in Police Districts 19
2.3.1 Hours spent RBT testing and numbers of tests conducted 192.3.2 Car and bus-based operations 20
2.4 Summary of RBT Operations 21
REFERENCES 21
Appendix A Location of Metropolitan and rural police districts
Appendix B RBT Operations in Police Districts
AN OVERVIEW OF RANDOM BREATH TESTING OPERATIONS ... V
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Acknowledgements
This analysis of Random Breath Testing operations was madepossible by the provision of data by
Victoria Police staff of the Traffic Alcohol Section.
AN OVERVIEW OF RANDOM BREATH TESTING OPERATIONS ... VU
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EXECUTIVE SUMMARY
Since its inception in 1976, random breath testing (RBT) operations had been
primarily car-based. As part ofthe RBT Initiative (commencing towards the end
of 1989), the Victoria Police took progressive delivery of 13 highly visible,
purpose built buses from which to conduct RBT operations. Operational data
from the initiative have been made available to monitor the changes in police
operations as the initiative evolved. RBT operational data from July 1989 to June
1991, covering the period where buses were introduced, have been used tomonitor these changes.
The main change in RBT activity over the two years was the increased usage ofbuses and the resultant decrease in car-based testing. In the metropolitan area thechange to buses was almost immediate while the introduction of buses to ruralVictoria was much slower and varied across police districts.
The introduction of buses has led to increases in the number of RBT tests and
gradual, but relatively smaller, increases in the total number of hours of RBToperations and session duration in the metropolitan area. In the rural areas thenumber of tests and duration of RBT sessions have, until early 1991, remainedrelatively constant. The number of hours spent testing in rural areas has variedover time.
The main change due to the introduction of buses for the purpose ofRBT has beena large increase in the number of people tested for only small changes in the totaltime spent testing.
AN OVERVIEW OF RANDOM BREATH TESTING OPERATIONS •.. IX
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1.0 INTRODUCTION
Random Breath Testing (RBT) originally was introduced to Victoria in 1976 and involved
random breath testing drivers, for alcohol levels, from police cars. Towards the end of 1989
the Victoria police began to use highly visible, purpose-built buses from which to conduct RBT
operations. Previously testing was primarily car-based, although four Toyota Coaster buseswere also used. Operational data from July 1989 to June 1991 was made available to monitor
the changes brought about by the introduction of bus-based RHT testing.
The RHT initiative has been evaluated to determine the effect the program has had on road
accidents (Drummond, Sullivan & Cavallo, 1992; Cameron, Cavallo & Sullivan, 1992;Cavallo & Cameron, 1992). The operational data was essential to understand the exact natureof the program and to undertake the post-hoc quasi-experimental evaluation.
The extensive analysis of operational data also provides feedback to the agencies implementing
the initiative. This report provides a summary of RBT operations with graphical representa-tions of the data.
2.0 RBT INITIATIVE - OPERATIONAL DATA
An examination of the characteristics of RBT and a description of its operation in the periodfrom July 1989 to June 1991 for different areas in Victoria was undertaken to assist theevaluation of its effectiveness. The characteristics available for examination were:
• the number of hours of testing;
• the number of tests conducted;
• the ratio of bus-based and car-based RBT;
• session duration;
• time of day and day of week of operation; and
• the number of drivers detected with a positive reading.
2.1 RBT Operations Statewide
Information regarding RBT and preliminary breath testing (PBT) operations in each policedistrict in Victoria was obtained for the two year period from July 1989 to June 1991. PBToperations involve mobile intercepts and tests of drivers involved in crashes.
Between July 1989 to June 1991 there were:
17,625 RBT sessions
over 23,000 hours ofRBT testing
almost 1.8 million RBT tests
The number of RBT tests steadily increased over the two years while, at the same time, PBTtesting appeared to decrease somewhat after 1989 (Figure 2.1).
AN OVERVIEW OF RANDOM BREATH TESTING OPERATIONS ...
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Figure 2.1 RBT & PBT Tests
I_RBT OPBT I
300000
275000250000225000200000T 175000eS 150000ts 125000
1000007500050000250000July
Qet
to
to
Sep
Dee
'89'89
Janto
Mar
'90
Aprilto
June
'90
Julyto
Sep'90
Qct
to
Dee
'90
Jan
toMar
'91
Aprilto
June
'91
In contrast, hours of testing overall remained relatively constant, apart from increases when the
RBT initiative was first introduced (last quarter 1989) and at the beginning of 1991 (Figure
2.2).
The number of RBT tests conducted in Victoria since 1977 progressively increased over timewith a substantial increase from around 1;2 million tests in 1989 to over 900,000 in 1990 and 1.1million in 1991 as a result of the initiative.
Figure 2.2 RBT: Hours of Testing
4500
400035003000H
o 2500ur 2000s1500
10005000July
Qetto
toSep
Dec'89
'89
Janto
Mar'90
Aprilto
June'90
Julyto
Sep'90
Qctto
Dec'90
Janto
Mar'91
Aprilto
June'91
2 MONASH UNIVERSITY ACCIDENT RESEARCH CENTRE
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2.2 RBT in Metropolitan and Rural Victoria
In this study the metropolitan area is defined as police districts A to J, whilst remaining police
districts (K to Q) constitute rural areas. Maps of areas of the State which make up themetropolitan and rural police districts appear in Appendix A.
2.2.1 Hours of RBT testing
Overall, the total number of hours ofRBT testing was greater in rural Victoria (14,000 hours)than in the Melbourne metropolitan area (9,000 hours) over the two years. However, in the
metropolitan area hours of testing gradually increased to a level of around 480 hours per month
by 1991, whilst in the rural area, the number of hours spent testing was more variable,
decreasing throughout most of 1990. There were intensified efforts in rural Victoria in January
and March 1991 however, with over 1000 hours of testing in each month (Figure 2.3).
Figure 2.3 RBT - Monthly Number of Hours of Testing
1-- Metropolitan - Rest of State I1200
1000
,800
Hou 600rs
400
200
o
J A SON D J F M A M J J A SON D J F M A M J
1989 1990 1991
2.2.2 NumberofRBTtests
Overall, the metropolitan area had a much greater number of tests (1.2 million tests) than therural area (~million tests). The number of persons tested in the metropolitan area generallyincreased (to about 70,000 tests per month) while the numbers tested in the rural area remainedsteady at around 20,000 tests per month (Figure 2.4).
AN OVERVIEW OF RANDOM BREATH TESTING OPERATIONS ... 3
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Figure 2.4 RBT - Monthly Number of Persons Tested
1--- Metropolitan - Rest of State I80000
70000
P 60000er550000on
5 40000
Te5 30000te
d 20000
10000
o
J A SON 0 J F M A M J J A SON 0 J F M A M J
1989 1990 1991
2.2.3 Car and bus-based RBT operations
In late 1989, 13 new buses were purchased and fitted for the purpose of conducting RBT tests.The main differences between bus and car-based RBT testing is that there are more police
personnel operating each bus and the capacity for RBT testing is therefore increased.Calculations for the two year period show that bus-based RBT operations more than doubledthe testing rate of car-based RBT operations in both the metropolitan (154 tests per hour frombuses and 70 tests per hour from cars) and rural areas (89 tests per hour from buses and 31 testsper hour from cars).
There was a steady increase in both the proportion of RBT tests conducted and hours spenttesting out of buses. RBT testing in the metropolitan area shifted from being primarily car-based (80 to 90% of hours between July-September 1989) to almost completely bus-based,with cars accounting for less than 10% of hours, by September 1990 (Figures 2.5 and 2.6). Inthe metropolitan area bus-based RBT was the primary form of RBT operation since November1989 in terms of both hours of testing and number of tests conducted.
4 MONASH UNIVERSITY ACCIDENT RESEARCH CENTRE
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100%
80%
60%
40%
20%
0%
Figure 2.5 Metropolitan RBT Tests
'_car o Sus
J A SON D J F M A M J J A SON D
1989 1990
Figure 2.6 Metropolitan RBT Hours
I_car o Sus
F M A M J
1991
100%
80%
60%
40%
20%
0%
J A SON D1989
F M A M J J A SON 01990
F M A M
1991
AN OVERVIEW OF RANDOM BREATH TESTING OPERATIONS ... 5
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In contrast, RBT testing in the rural area changed from being almost completely car-based to
a level in which cars accounted for about 60% ofRBT hours by June 1991 (Figures 2.7 and 2.8).The trend of shifting towards buses in the rural area appeared to be continuing at the end of thetwo years.
Figure 2.7 Rural RBT Tests
I_car o Sus
J A SON D
1989
F M A M J
1990
A SON D F M A M J
1991
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
Figure 2.8 Rural RBT Hours
I_ear o Sus
J A SON 0 J F M A M J J A SON 0 J F M A M J
1989 1990 1991
6 MONASH UNIVERSITY ACCIDENT RESEARCH CENTRE
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2.2.4 RBT session duration
RBT session duration in the metropolitan area: There was an increase in session duration
over the two year time period as shown by the shifting distribution (Figures 2.9 to 2.12) and also
the average durations (Figure 2.13) for six monthly periods. In the period from July to
December 1989 the majority of sessions were under I hour in duration. The number of longer
sessions increased over time, with the majority of sessions lasting from I% to 3 hours and also
greater than 5 hours by mid-1990 and 1991. This trend was consistent with the gradual increase
in hours of operation over time and the number of sessions remaining relatively constant.
Figure 2.9 Metropolitan Session Duration Jut to Dee 1989
250
200
Se 15055ion 1005
50
0
1 to
161031 to4610611076109110106121151181211241271>
15
304560759010510latolatoto10300
mins
minsminsminsminsminsmins120150180210240270300mins
mins
minsminsminsminsminsmins
Figure 2.10 Metropolitan Session Duration Jan to Jun 1990
250
200
Se 15055Ion 1005
50
0
110
161031104610611076109110106121151181211241271
15
3045607590105tolato101010to300
mins
minsminsminsminsminsmins120150180210240270300mins
mins
minsminsminsminsminsmins
AN OVERVIEW OF RANDOM BREATII TESTING OPERATIONS ... 7
-
Figure 2.11 Metropolitan Session Duration Jul to Dee 1990
250
200
5e 150ssio
n 100s
50
0
110
16to31 to46 to61 to76 to91 to106121151181211241271>
15
3045607590105tototototototo300
mins
minsminsminsminsminsmins120150180210240270300mins
mins
minsminsminsminsminsmins
Figure 2.12 Metropolitan Session Duration Jan to Jun 1991
250
200
5e 150ssIon 100s
50
0
110
161031 to46 to61 to76 to91 to10612115118121124127115
3045607590105tototototototo300mins
minsminsminsminsminsmins120150180210240270300minsmins
minsminsminsminsminsmins
8 MONASH UNIVERSITY ACCIDENT RESEARCH CENTRE
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Figure 2.13 Metropolitan Area Mean Session Duration
180
160
140
120
M
I 100nute 80
5
60
40
20
o
Jut to Dec '89 Jan to Jun '90 Jul to Dec '90 Jan to Jun '91
RBT session duration in the rural area: Session duration did not change greatly (Figures2.14 to 2.17). The vast majority of sessions in rural Victoria were less than I hour in duration,although, in the first half of 1991 there was an increase in the number of sessions greater thanfive hours in duration. The average session duration decreased until the first half of 1991(Figure 2.18).
Figure 2.14 Rural Session Duration Jut to Dec 1989
1200
1000
800
S ess600I 0ns 400
200
o
1 to 16 to31 to46 le'31 to7'.3 t815
3D45
mms
rTllnSmi;,S '''IriS'T1:ns
-
Figure 2.15 Rural Session Duration Jan to Jun 1990
1200
1000800
S ess 600I0ns 400
200
0
1 to
16to31 to46 to61 to76 to91 to106121151181211241271>
15
3045607590105tototototototo300
mins
minsminsminsminsminsmins120150180210240270300mins
mins
minsminsminsminsminsmins
Figure 2.16 Rural Session Duration Jul to Dee 1990
1200
1000
800S e55
600I 0n5 400
200
0
1 to
16to31 to46 to61 to76 to91 to10612115118121124127115
3045607590105tototototototo300mins
minsminsminsminsminsmins120150180210240270300minsmins
minsminsminsminsminsmms
10 MONASH UNIVERSITY ACCIDENT RESEARCH CENTRE
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Figure 2.17 Rural Session Duration Jan to Jun 1991
1200
1000
800
S ess600I 0ns 400
200
0
110
16to31 to46 to611076 to91 to106121151181211241271>15
304560759010510101010101010300mins
minsminsminsminsminsmins120150180210240270300minsmins
minsminsminsminsminsmins
Figure 2.18 Rural Area Mean Session Duration
90
80
70
60
M
150nu
t 40es
30
20
10
o
Jul to Dec '89 Jan to Jun '90 Jul to Dec '90 Jan to Jun '91
AN OVERVIEW OF RANDoM BREATH TESTING OPERATIONS ... 11
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Bus and car-based session duration: Whilst the average session duration of buses operatingin the rural area remained at around two hours, the distribution has changed over time with anincrease in the number of bus sessions less than one hour and also greater than five hours. Theduration of bus sessions in the metropolitan area did not change over the two year period witha mean duration of over 3 hours. Car session duration was also steady over the period in both
the metropolitan and rural areas with the majority of sessions being under 1 hour in duration.
The increase in session duration in the metropolitan area appeared to be the result ofthe shiftfrom predominantly car-based operations to almost totally bus-based operations which weretypically longer in duration. Since the shift towards buses was slower in the rural area the
introduction of the buses had relatively little effect on session duration in these areas until thefirst half of 1991.
2.2.5 Start/end times of RBT sessions
The start times in the metropolitan area did not greatly change with a median start time between
7pm and 8pm. Over that time period RBT operations tended to finish later with the median
finish time shifting from about 9pm in the last six months of 1989 to 11pm in the first six months
of 1991 (Figures 2.19 to 2.22). It appeared that the increase observed in session duration in
the metropolitan area was the result of the sessions running later. There was a reduction in the
level of testing during late morning and early afternoon.
In the rural area the start and end times ofRBT sessions did not greatly change. (Figures 2.23
to 2.26).
Figure 2.19 Metropolitan Start/End Times Jul to Dee 1989
I_ Start Hour 0 End Hour250
200
Se 150ssion 100s
50
o
o 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23
Hour Beginning
12 MONASH UNIVERSITY ACCIDENT RESEARCH CENTRE
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250
200
Se 15055I
'0
n 1005
50
o
250
200
Se 1S055Ion 1005
50
o
Figure 2.20 Metropolitan StartJEnd Times Jan to Jun 1990
I_ Start Hour 0 End Hour
o 1 2 3 4 S 6 7 8 9 10 11 12 13 14 1S 16 17 18 19 20 21 22 23
Hour Beginning
Figure 2.21 Metropolitan StartJEnd Times Jut to Dee 1990
I_ Start Hour D End Hour
o 1 2 3 4 S 6 7 8 9 10 11 12 13 14 1S 16 17 18 19 20 21 22 23
Hour Beginning
AN OVERVIEW OF RANDOM BREATH TESTING OPERATIONS ... 13
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Figure 2.22 Metropolitan StartlEnd Times Jan to Jun 1991
I_ Start Hour 0 End Hour250
200
Se 150ssio
n 100s
50
o
o 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23
Hour Beginning
Figure 2.23 Rural StartlEnd Times Jul to Dec 1989
I_ Start Hour 0 End Hour
2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23
Hour Beginning
700
600500
Se40055i0300n5
200
1000
0
14 MONASH UNIVERSITY ACCIDENT RESEARCH CENTRE
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700
600SOD
Se40055I°300n5
200
1000
0
700
600500
Ses 400sI0300ns
200
1000
0
Figure 2.24 Rural StartlEnd Times Jan to Jun 1990
/_ start Hour 0 End Hour
2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23
Hour Beginning
Figure 2.25 Rural Start/End Times Jul to Dee 1990
I_ start Hour 0 End Hour
2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23
Hour Beginning
AN OVERVIEW OF RANDOM BREATH TESTING OPERATIONS ... 15
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Figure 2.26 Rural StartlEnd Times Jan to Jun 1991
\_ Start Hour 0 End Hour700
600
500
S
e 40055i0300n5
200
100
o
o 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23
Hour Beginning
2.2.6 RBT by day of week
In the metropolitan area Thursday, Friday and Saturday are the days with the highest number
of hours of RBT testing. RBT operations became even more concentrated on these days as
compared to the earlier part of the week (Figure 2,27) although there were substantial periods
of time spent testing on each day of week. The emphasis of time spent in rural RBT testing
shifted from Friday, Saturday and Sunday to be more in line with the metropolitan area (Figure2.28).
Figure 2.27 Metropolitan RBT Hours by Day of Week
• Jul to Dec '89 0 Jan to Jun '90 _ Jul to Dec '90 0 Jan to Jun '91
MONASH UNIVERSITY ACCIDENT RESEARCH CENTRE
600
500400
H
0u 300r5
200
100016
Sunday Monday Tuesday Wednesday Thursday Friday Saturday
-
Figure 2.28 Rural RHT Hours by Day of Week
IIIJul to Dec '89 0 Jan to Jun '90 • Jul to Dec '90 0 Jan to Jun '91
1000
900800700600
H 0u 500rs 400
3002001000
Sunday
2.2.7 PBT
Monday Tuesday Wednesday Thursday Friday Saturday
There is very little information available about PBT tests (tests from mobile intercepts andcrash involved drivers) conducted in the two year period except for the number tested inmetropolitan and country areas each month. It should be noted that metropolitan and countryare Police definitions and differ slightly from the definitions used previously.
Of the 919,450 PBT tests conducted 62% occured in metropolitan areas while the remaining38% ofPBT tests were in country Victoria.
2.2.8 Hit rates
The RBT hit rate (percentage of positive BAC tests) in the metropolitan area over the two yearperiod (0.25 to 0.40%) was consistently higher than in rural Victoria (0.10 to 0.15%) as shownin Figure 2.29. For both areas the hit rate varied somewhat over this period with no clear upwardor downward trends. The hit rate for PBT (3 to 4%) is much higher than for RBT but, as withRBT, there was no obvious trend (Figure 2.30).
AN OVERVIEW OF RANDOM BREATH TESTING OPERATIONS ... 1 7
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Figure 2.29 RBT Hit Rate (Positive BAC) - Metropolitan v. Rural
1_ Metropolitan - Rest of Stat~ I0.50
0.45
0.40
0.35
%
P 0.30
o
5I 025t
i 0.20V
e0.15
0.10
0.05
0.00
J A SON D
1989
F M A M J
1990
A SON D J F M A M
1991
6.00
5.00
% 4.00
po
s 3.00ItIve 2.00
1.00
0.00
Figure 2.30 PBT Hit Rate (Positive BAC) - Metropolitan v. Country
1-Metropolitan - Country
J A SON 01989
F M A M J
1990
A SON 0 F M A M1991
18 MONASH UNIVERSITY ACCIDENT RESEARCH CENTRE
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2.3 RBT in Police Districts
2.3.1 Hours spent RBT testing and numbers ottests conducted
The number of hours spent testing and the total number of RBT tests conducted within each
police district were examined (Figures 2.31 and 2.32).
Figure 2.31 Hours ofRBT Testing
,_ Division 1 0 Division 23500
3000
2500
H 2000our51500
1000
500
o
AB CD E F G H
Metropolitan
K L M N 0 P aRest of State
250000
200000
150000Te5t5
100000
50000
o
Figure 2.32 RBT Tests
I_ Division 1 0 Division 2
AB C D E F G H
Metropolitan
K L M N 0 P aRest of State
AN OVERVIEW OF RANDOM BREATH TESTING OPERATIONS ... 19
-
Districts in the metropolitan area spent similar amounts of time RBT testing and conducted
similar numbers of tests per hour (Figure 2.33). In districts A, B and C there were more testsconducted each hour, in comparison to other districts. This can be explained by the highertraffic volumes in these districts which are located in and around the inner metropolitan area.
Districts D, E and F recorded the lowest number of tests per hour.
Figure 2.33 RBT - Rate of Testing in Police Districts
I_ Division 1 0 Division 2160
140
T 120•st 100s
P 80•r
H 60our 40
20
o
A BeD E F G H
Metropolitan
K M N 0 P Q
Rest of state
In the different rural police districts there was marked variation in the number of hours spenttesting and the number of tests conducted. When broken down into the different divisions itcan be seen that the majority ofRBT in some rural districts was concentrated mainly in one ofthe divisions, generally the one closer to Melbourne. This is most evident in districts M and0, the two districts immediately north west of the metropolitan area.
2.3.2 Car and bus-based operations
The introduction of buses occurred almost immediately in all of the metropolitan policedistricts while their introduction to rural areas was slower and at varying times across policedistricts. Some rural districts/divisions began introducing buses early in 1990 while otherdistricts/divisions first began to use them in late 1990 or early 1991.
A detailed analysis of the number and proportion of hours and tests conducted from car and bus-based operations, for each individual police district, is presented in Appendix B.
In closely scrutinising the amount of bus use in the different police districts and divisions itappears that the type of RBT in a district can be categorised into one of three models. Themetropolitan districts were all similar, in that they moved to buses very quickly. In the ruralarea there appeared to be some districts/divisions that introduced low levels of bus based RBTin late 1989/early 1990 with the remaining areas making very little use of buses until, at least,late 1990.
20 MONASH UNIVERSITY ACCIDENT RESEARCH CENTRE
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2.4 Summary of RBT Operations
The main change in RBT activity over the two years was the increased usage of buses and the
decrease in car-based RBT. The introduction of buses almost immediately substituted car-
based RBT in all police districts in the metropolitan area while their introduction in the rural
area was much slower and varied across police districts.
This led to a much higher number of RBT tests and gradual, but relatively smaller, increases
in the total number of hours ofRBT operations and session duration in the metropolitan area.
In rural Victoria, the number ofRBT tests conducted and the duration ofRBT sessions (until
1991) remained relatively constant, even though the number of hours spent testing was variable
over time. In some rural areas bus-based RBT was used at low levels whilst at the remaining
rural locations bus-based RBT was not used consistently until late 1990/early 1991. Overall
in Victoria this resulted in a substantial increase in the number of RBT tests for only gradual
changes in the time spent testing.
REFERENCES
Cameron, M.H., Cavallo A., & Sullivan, G. 1992, Evaluation of the Random Breath TestingInitiative in Victoria 1989-1991. Multivariate Time Series Approach, Report No. 38, MonashUniversity Accident Research Centre, Clayton, Victoria
Cavallo, A., & Cameron, M.H. 1992,Evaluation of a Random Breath Testing Initiative inVictoria 1990 & 1991. Summary Report, Report No. 39, Monash University AccidentResearch Centre, Clayton, Victoria
Drummond, A.E., Sullivan, G., & Cavallo, A. 1992, Evaluation of a Random Breath TestingInitiative in Victoria 1989-1990. Quasi-experimental time series approach, Report No. 37,Monash University Accident Research Centre, Clayton, Victoria
AN OVERVIEW OF RANDOM BREATH TESTING OPERATIONS ... 21
-
Location of Metropolitan andRural Police Districts
Appendix A
-
flt'B~
2
~ -",..r
1
pIMOUNTAINS
LEGEND
- DISTRIcr BOUNDARIES
DIVISIONAL BOUNDARIES
,,~
-
z.-'
..
DISTRICT BOUNDARIES
'....." .
2
DIVISIONAL BOUNDARIES
e ••.•••.••••
.......•.. ~~.
LEGEND
Q
-17/./W\}
2
IllGHLANDS WIMMERA
2
1
N
MIiIiIIjI!IIii!
IIIIII
IjiI!I\II1
1Ii
-
Appendix B
RBT Operations in Police Districts
-
-j;-
Police District A
Number of RBT tests from Cars and Buses
IDear • Bus
8000
6000
4000
2000
o
J A SON 0 J F M A M J J A SON 0 J F M A M J
July 89 - June 91
Police District A
Proportion of RBT tests from Cars and Buses
I Dear • Bus
100%".-
90"k
80%
70%
60%
50%
40%
30%
20"k
10%
11
I
IIJ A SON 0 J F M A M J J A SON 0 J F M A M J
July 88- June 81
-
Police District A
Number of Minutes of Car and Bus based RBT
IDear • Bus I
71
6000
5000
4
3000
2
I
I1
.~
•IfIrorI.r
~r rIr.r.r.r
J ASONDJ FMAMJ J ASONDJ FMAMJ
July 89 - June 91
Police District A
Proportion of Car and Bus based RBT Minutes
loear • Bus I
100o/in III6O"1c
40%
~
20%·
.-lj
J A SON 0 J F M A M J J A SON 0 J F M A M J
July 89 - June 91
-
Police District B
Number of RBT tests from Cars and Buses
loeM • Bus I
8000
6000
4000
2000
o
J ASONDJ FMAMJ J ASONDJ FMAMJ
July 89 - June 91
Police District B
Proportion of RBT tests from Cars and Buses
IOear • Bus
100%,.,.-
60%
I20%
J A SON D J F M A M J J A SON D J F M A M JJuly 89 - June 91
-
Police District B
Number of Minutes of Car and Bus based RBT
IDear • Bus I
9000
8000
7000
6000
5000
4000
3000
2000
o
J ASONDJ FMAMJ J ASONDJ FMAMJ
July 89 • June 91
Police District B
Proportion of Car and Bus based RBT Minutes
locar • Bus
l00%~
90%
80%
70%
60%
50%
40%
30%
20%
10%
-
J A SON D J F M A M J J A SON D J F M A M JJuly 811 • June III
-
8000
6000
4000
Police District C
Number of RBT tests from Cars and Buses
IOcar • Bus
o
J A SON 0 J F M A M J J A SON 0 J F M A M J
July89-June91
Police District C
Proportion of RBT tests from Cars and Buses
ID Car • Bus
100%
80%
60%
40%
20%
0%
J A SON 0 J F M A M J J A SON 0 J F M A M JJuly 811· June 111
-
9000
8000
7000
6000
5000
4000
3000
2000
o
100%
80%
60%
40%
20%
0%
Police District C
Number of Minutes of Car and Bus based RBT
IDear • Bus I
J ASONDJ FMAMJ J ASONDJ FMAMJ
July 89 • June 91
Police District C
Proportion of Car and Bus based RBT Minutes
IOear • Bus I
J ASONDJ FMAMJ J ASONDJ FMAMJ
July 88 • June 81
-
8000
6000
4000
o
100%'
80%
60%
40%
20%
0%
Police District D
Number of RBT tests from Cars and Buses
jocar • Bus
J ASONDJ FMAMJ J ASONDJ FMAMJ
July 89 - June 91
Police District D
Proportion of RBT tests from Cars and Buses
IDear • Bus
J A SON 0 J F M A M J J A SON 0 J F M A M J
July 811-Junelll
-
9000
8000
7000
6000
5000
4000
3000
2000
o
100"10
80%
60%
40%
20%
0%
Police District D
Number of Minutes of Car and Bus based RBT
IDear .Bus I
J ASONDJ FMAMJ J ASONDJ FMAMJ
July 89 - June 91
Police District D
Proportion of Car and Bus based RBT Minutes
10 Car • Bus I
J ASONDJ FMAMJ J ASONOJ FMAMJ
July 89 - June 81
-
8000
6000
4000
Police District E
Number of RBT tests from Cars and Buses
Io ear • Bus I
2000
o
100%
80%
60%
40%
20%
0%
J ASONDJ FMAMJ J ASONDJ FMAMJ
July 89 • June 91
Police District E
Proportion of RBT tests from Cars and Buses
I o ear • Bus I
J ASONDJ FMAMJJASONDJ FMAM,'
July 88 • June 81
-
'-t::'.-.:~.
9000
8000
7000
5000
4000
3000
2000
o
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
Police District E
Number of Minutes of Car and Bus based RBT
IDCar • Bus I
J A SON 0 J F M A M J J A SON 0 J F M A M J
July 89 - June 91
Police District E
Proportion of Car and Bus based RBT Minutes
I o ear • Bus I
J A SON 0 J F M A M J J A SON 0 J F M A M J
July 89 - June 91
-
8000
6000
4000
2000
o
Police District F
Number of RBT tests from Cars and Buses
Io ear • Bus
J A SON D J F M A M J J A SON D J F M A M J
July 89 - June 91
Police District F
Proportion of RBT tests from Cars and Buses
I Dear • Bus
100%,..,-, ,-, _ ,-, _ r-
90%80%70%60%50"k40%30%20%~ ;; ; ~; ; ~; ; ~; ; ~ ~ III10%-H 11 11 I 1 I. 1 I. I 11 11 11 I ••0%
J ASONDJ FMAMJ J ASONDJ FMAMJ
July 89 - June 91
-
Police District F
Number of Minutes of Car and Bus based RBT
IDear .Sus I
9000
8000
7000
6000
5000
4000
3000
2000
1000
o
J ASONDJ FMAMJJ ASONDJ FMAMJ
July 89 • June 91
Police District F
Proportion of Car and Bus based RBT Minutes
I Dear • Bus I
100%,.,......, .--
90%
80%
70%
60%
50%
40%
30%
20"'{'
r- r-
-
10%
J A SON D J F M A M J J A SON 0 J F M A M J
July 89 • June 91
-
8000
6000
4000
Police District G
Number of RBT tests from Cars and Buses
IDear • Bus I
2000
o
J ASONDJ FMAMJ J ASONDJ FMAMJ
July 89 • June 91
Police District G
Proportion of RBT tests from Cars and Buses
I Dear • Bus
40%
20%
00;;'
J ASONDJ FMAMJ J ASONDJ FMAMJ
July 1111 • June 111
-
9000
8000
7000
6000
5000
4000
3000
2000
o
Police District G
Number of Minutes of Car and Bus based RBT
IDear • Bus I
J A SON 0 J F M A M J J A SON 0 J F M A M J
July 89 - June 91
Police District G
Proportion of Car and Bus based RBT Minutes
I Dear • Bus I
60%
40%
20%
0%
J ASONDJ FMAMJ J ASQNDJ FMAMJ
July 88 - June 81
-
8000
6000
4000
o
100%
90"k
80%
70%
60%
50%
40%
30%
20%
10%
0%
Police District H
Number of RET tests from Cars and Buses
Io ear • Sus I
J ASONDJ FMAMJ J ASONDJ FMAMJ
July 89 - June 91
Police District H
Proportion of RBT tests from Cars and Buses
I Dear • Bus
J ASONDJ FMAMJ J ASONDJ FMAMJ
July 88 • June III
-
9000
8000
7000
6000
5000
4000
3000
2000
Police District H
Number of Minutes of Car and Bus based RBT
IDCar .Bus I
1000
o
J ASONDJ FMAMJ J ASONDJ FMAMJ
July 89 • June 91
Police District H
Proportion of Car and Bus based RBT Minutes
100%
80%
60%
40%
20%
0%
J A SON 0 J F M A M J J A SON 0 J F M A M JJuly 88 - June 81
-
Police District I
Number of RBT tests from Cars and Buses
loear • Bus I
8000
6000
4000
2000
o
J A SON 0 J F M A M J J A SON 0 J F M A M J
July 89 • June 91
Police District I
Proportion of RBT tests from Cars and Buses
100%1
90%
80%
70%
60%
50%
40%
30%
20%
10%
•
-
I°ear • Bus
4J
-
-•
nJ A SON 0 J F M A M J J A SON 0 J F M A M J
July 88 • June 81
-
Police District I
Number of Minutes of Car and Bus based RBT
IDear .Sus I
9000
8000
7000
6000
5000
4000
3000
2000
o
J ASONDJ FMAMJ J ASONDJ FMAMJ
July 89 - June 91
Police District I
Proportion of Car and Bus based RBT Minutes
JOcar • Bus I
•
I··············
III I'-Ir-"J A SON 0 J F M A M J J A SON 0 J F M A M J
July 88 - June III
100%]11-90%80%70%60%50%40%30%200k10%0%
-
8000
6000
4000
o
Police District J
Number of RBT tests from Cars and Buses
I o Car • Bus
100%
80%
J A SON D J F M A M J J A SON D J F M A M J
July 89 - June 91
Police District J
Proportion of RBT tests from Cars and Buses
IOear • Bus
60%
40%
20%
0%
J A SON D J F M A M J J A SON D J F M A M JJuly 89 - June 91
-
9000
8000
7000
6000
5000
4000
3000
2000
o
100%
80%
60%
40%
20%
0%
Police District J
Number of Minutes of Car and Bus based RBT
IDear • Bus
JASONDJFMAMJJASONDJ FMAMJ
July 89 • June 91
Police District J
Proportion of Car and Bus based RBT Minutes
I Dear • Bus I
JASONDJFMAMJJASQNDJ FMAMJ
July 811- June 111
-
8000
6000
4000
2000
o
100%
80%
60%
40%
20%
0%
Police District Kl
Number of RBT tests from Cars and Buses
loear • Bus I
J ASONDJ FMAMJ JASONDJ FMAMJ
July 89 - June 91
Police District Kl
Proportion of RBT tests from Cars and Buses
I o ear • Bus I
J ASONDJ FMAMJ J ASONDJ FMAMJ
July 811- June 111
-
9000
8000
7000
6000
5000
4000
3000
2000
Police District Kl
Number of Minutes of Car and Bus based RBT
10 Car • Bus I
1000
o
100"10
80%
60%
40%
20%
0%
J A SON 0 J F M A M J J A SON 0 J F M A M J
July 89 • June 91
Police District Kl
Proportion of Car and Bus based RBT Minutes
10 Car • Bus I
- ~-- - ~ -
-
J A SON 0 J F M A M J J A SON 0 J F M A M J
July 89 • June 91
-
8000
6000
4000
Police District K2
Number of RBT tests from Cars and Buses
IOear • Bus
2000
o
J A SON 0 J F M A M J J A SON 0 J F M A M J
July 89 • June 91
Police District K2
Proportion of RBT tests from Cars and Buses
I o ear • Bus
100''
-
9000
8000
7000
6000
5000
4000
3000
2000
1000
o
100%
40%
20%
0%
Police District K2
Number of Minutes of Car and Bus based RBT
IDCar • Bus I
J ASONOJ FMAMJ J ASONOJ FMAMJ
July 89 • June 91
Police District K2
Proportion of Car and Bus based RBT Minutes
I Dear • Bus I
r- - - .r-I---.-r-I-
~
J A SON 0 J F M A M J J A SON 0 J F M A M J
July 89 • June 91
-
Police District Ll
Number of RBT tests from Cars and Buses
IDear • Bus
8000
6000
4000
o
J A SON 0 J F M A M J J A SON 0 J F M A M J
July 89 - June 91
Police District L 1
Proportion of RBT tests from Cars and Buses
I Dear • Bus
,. - - ~------ •-r---1""'\
90010
100%
80%
70%
60%
50%
40%
30%
20010
10%
0%
J A SON 0 J F M A M J J A SON 0 J F M A M J
July 89 - June 91
-
9000
8000
7000
6000
5000
4000
3000
2000
Police District L 1
Number of Minutes of Car and Bus based RBT
IDear • Bus
1000
o
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
J A SON D J F M A M J J A SON D J F M A M J
July 89 • June 91
Police District Ll
Proportion of Car and Bus based RBT Minutes
I Dear • Bus
;- - ;-- ;-
--'--1•- -- •
~
JASONDJFMAMJJASONDJ FMAMJ
July 88 - June 81
-
8000
6000
4000
o
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0"10
Police District L2
Number of RBT tests from Cars and Buses
IDear • Sus I
J ASONDJ FMAMJ J ASONDJ FMAMJ
July 89 - June 91
Police District L2
Proportion of RBT tests from Cars and Buses
IOear • Bus
- - r- ~----- --- --I•
-
J ASONDJ FMAMJ J ASONDJ FMAMJ
July 89 - June 91
-
Police District L2
Number of Minutes of Car and Bus based RBT
Io ear • Sus
9000
8000
7000
6000
5000
4000
3000
2000
1000
o
J ASONDJ FMAMJ J ASONDJ FMAMJ
July 89 - June 91
Police District L2
Proportion of Car and Bus based RBT Minutes
I Dear
1OO%-rr---1 ,---, r-l .-. ,......,,---,r-l ,--, r--l r--'1 r--
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
• Bus
~roroll·
J ASONDJ FMAMJ J ASONDJ FMAMJ
July 89 • June 81
-
8000
6000
4000
Police District Ml
Number of RBT tests from Cars and Buses
IOear I Sus
2000
o
J A SON D J F M A M J J A SON 0 J F M A M J
July 89 • June 91
Police District Ml
Proportion of RBT tests from Cars and Buses
10 Car • Bus
100%
90%
80%
70%
60%
50%
40%
20%
10%
0%
-c--c-.c- 1-·••••I-
~-
JASONDJ FMAMJ J ASONDJ FMAMJ
July 88 ·June81
-
5000
6000
8
7
4,
3
2
Police District Ml
Number of Minutes of Car and Bus based RBT
IDear • Bus I
}
I
L
I,..,I, I,tI, I
I.I.11.I.I.
J ASONDJ FMAMJ J ASONDJ FMAMJ
July 89 - June 91
Police District Ml
Proportion of Car and Bus based RBT Minutes
IDear • Bus I
100%
80%
60%
40%
20%
0%
------II~I-I-.- - III
J ASONDJ FMAMJ J ASONDJ FMAMJ
July all- June III
-
8000
6000
4000
2000
o
80%
60%
40%
20%
0%
Police District M2
Number of RBT tests from Cars and Buses
IDear • Bus
J ASONDJ FMAMJ J ASONDJ FMAMJ
July 89 - June 91
Police District M2
Proportion of RBT tests from Cars and Buses
IDear • Bus
- ---~- ----r-- ---- •- -
J ASONDJ FMAMJ JASONDJ FMAMJ
July 811-June 91
-
9000
8000
7000
6000
5000
4000
3000
2000
o
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
Police District M2
Number of Minutes of Car and Bus based RBT
IDear • Sus
J ASONDJ FMAMJ J ASONDJ FMAMJ
July 89 - June 91
Police District M2
Proportion of Car and Bus based RBT Minutes
IDear • Bus
- r- -r--r- r--r--r- r---r-I- ---
J A SON 0 J F M A M J J A SON 0 J F M A M J
July 89 - June 91
-
8000
6000
4000
Police District NI
Number of RBT tests from Cars and Buses
IDear • Bus
2000
o
100%
80%
60%
40%
20%
0%
J ASONDJ FMAMJ J ASONDJ FMAMJ
July 89 • June 91
Police District NI
Proportion of RBT tests from Cars and Buses
I Dear • Bus
- r- --~-----------
J A SON 0 J F M A M J J A SON 0 J F M A M J
July 88 - June 91
-
9000
8000
7000
6000
5000
4000
3000
2000
Police District NI
Number of Minutes of Car and Bus based RBT
IDear • Bus
1000
o
J A SON 0 J F M A M J J A SON 0 J F M A M J
July 89 - June 91
Police District NI
Proportion of Car and Bus based RBT Minutes
IOear • Bus
100%
600/0
40%
20%
0%
r- - r--- r-- r-----r---r--- •
J A SON 0 J F M A M J J A SON 0 J F M A M JJuly ae • June 81
-
8000
6000
4000
2000
Police District NZ
Number of RBT tests from Cars and Buses
10 Car • Bus
o
J A SON D J F M A M J J A SON D J F M A M JJuly 89 - June 91
Police District N2
Proportion of RBT tests from Cars and Buses
jocar • Bus
100%
60%
60%
40%
20%
0%
- --•.---;------- -~-.----I .--
J A SON D J F M A M J J A SON D J F M A M J
July 89 - June 91
-
9000
8000
7000
6000
sooo
4000
3000
2000
Police District N2
Number of Minutes of Car and Bus based RBT
IDear • Bus
1000
o
J ASONDJ FMAMJ J ASONDJ FMAMJ
July 89 • June 91
Police District N2
Proportion of Car and Bus based RBT Minutes
~r • Bus
100%
80%
60%
40%
20%
- -~Ir--r--~-~- --r--r--I --
J A SON D J F M A M J J A SON 0 J F M A M J
July 89· June 91
-
8000
6000
.4000
o
Police District 01
Number of RBT tests from Cars and Buses
I°Car • Bus
J A SON D J F M A M J J A SON D J F M A M J
July 89 • June 91
Police District 01
Proportion of RBT tests from Cars and Buses
~ar • Sus
100%'_~---~-- - • I80%
60%
40%
20%
0%
J ASONDJ FMAMJ J ASONDJ FMAMJ
July 89 • June 91
-
6000
5000
4
3
2
Police District 01
Number of Minutes of Car and Bus based RBT
IDear • Bus I
I, .,I, I, .,•I,I.I,.,I, I, I..J A SON 0 J F M A M J J A SON 0 J F M A M J
July 89 • June 91
Police District 01
Proportion of Car and Bus based RBT Minutes
I o ear • Sus I
90%
100%
·--~·~--~II-IIIIII -. I80%
70%
60%
50%
40%
30%
20%
10%
0%
J A SON 0 J F M A M J J A SON 0 J F M A M J
July 89 - June 91
-
8000
6000
4000
Police District 02
Number of RBT tests from Cars and Buses
IOear • Bus
o
J ASONDJ FMAMJ J ASONDJ FMAMJ
July 89 - June 91
Police District 02
Proportion of RBT tests from Cars and Buses
I Dear • Bus
100%
80%
60%
40%
20%
0%
r- - r- -- .---- .---- r-e--r-- -
-
~
J ASONDJ FMAMJ J ASONDJ FMAMJ
July 89 - June 91
-
9000
8000
7000
6000
5000
4000
3000
2000
1000
o
Police District 02
Number of Minutes of Car and Bus based RBT
IDCar • Bus I
J ASONDJ FMAMJ J ASONDJ FMAMJ
July 89 • June 91
Police District 02
Proportion of Car and Bus based RBT Minutes
I DCar • Bus
100%
80%
40%
20%
0%
- ~- ,..--r--r--~- --~I
-
~
J ASONDJ FMAMJ J ASONDJ FMAMJ
July 811· June III
-
Police District PI
Number of RBT tests from Cars and Buses
I DCar • Bus I
8000
6000
4000
o
J ASONDJ FMAMJ J ASONDJ FMAMJ
July 89 - June 91
Police District PI
Proportion of RBT tests from Cars and Buses
IOcar • Bus
,- ~ -~-~-- - ~-- II- I-
-
,
80%
60%
20%
100%
0%
J A SON 0 J F M A M J J A SON 0 J F M A M J
July 89 - June 91
-
Police District PI
Number of Minutes of Car and Bus based RBT
IDear • Bus I
9000
8000
7000
6000
5000
4000
3000
2000
1000
o
J ASONDJ FMAMJ J ASONDJ FMAMJ
July 89 - June 91
Police District PI
Proportion of Car and Bus based RBT Minutes
IDCar • Bus
100%n-0 ~ ~ • n n n n n ~ n n Inn I~11~nil40%
20%
J ASONDJ FMAMJ JASONDJ FMAMJ
July 89 • June 91
-
8000
6000
4000
o
100%
80%
60%
40%
20%
0%
Police District P2
Number of RBT tests from Cars and Buses
Io Car I Sus
J A SON 0 J F M A M J J A SON 0 J F M A M J
July 89 - June 91
Police District P2
Proportion of RBT tests from Cars and Buses
I Dear • Bus
---- 1- r-- - -
-
,~, -
J A SON 0 J F M A M J J A SON 0 J F M A M J
July 89 - June 111
-
9000
8000
7000
6000
5000
4000
3000
2000
1000
o
100%
80%
60%
40%
20%
0%
Police District P2
Number of Minutes of Car and Bus based RBT
jocar • Bus
J A SON D J F M A M J J A SON D J F M A M J
July 89 - June 91
Police District P2
Proportion of Car and Bus based RBT Minutes
IDear • Bus
--~-II-I -- - --
-
J A SON D J F M A M J J A SON D J F M A M J
July 89 • June 81
-
8000
6000
4000
Police District Q 1Number of RBT tests from Cars and Buses
IOear • Bus
2000
o
J A SON 0 J F M A M J J A SON 0 J F M A M J
July 89 - June 91
Police District Ql
Proportion of RBT tests from Cars and Buses
IOear • Bus
,-- - -,--,---- -II ~80%
60%
40%
20%
0%
J ASONDJ FMAMJ J ASONDJ FMAMJ
July 89 - June 91
-
9000
8000
7000
6000
5000
4000
3000
2000
1000
o
100%
80%
60%
40%
20%
Police District Q 1Number of Minutes of Car and Bus based REI
IDear • Bus I
J A SON 0 J F M A M J J A SON 0 J F M A M J
July 89 - June 91
Police District Q 1
Proportion of Car and Bus based RBT Minutes
10 Car • Bus
--r--r---~-
1- -11-
P""'\
~-
J ASONDJ FMAMJ J ASONDJ FMAMJ
July 811• June III
-
8000
6000
4000
o
100%
90%
80%
70%
60%
50"10
40%
30%
20%
10%
0%
Police District Q2Number of RET tests from Cars and Buses
IDear • Bus
J ASONDJ FMAMJ J ASONDJ FMAMJ
July 89 • June 91
Police District Q2
Proportion of RBT tests from Cars and Buses
Io ear • Bus
r- --- - r-- -~-
~
J A SON 0 J F M A M J J A SON 0 J F M A M J
July 89 • June 91
-
9000
8000
7000
6000
5000
4000
3000
2000
o
100%
80%
60%
40%
20%
0%
Police District Q2Number of Minutes of Car and Bus based RBT
IDear • Bus
J A SON 0 J F M A M J J A SON 0 J F M A M JJuly 89 • June 91
Police District Q2
Proportion of Car and Bus based RBT Minutes
10 Car • Bus
r- --r-Ir-- r- I- --
-i
J A SON 0 J F M A M J J A SON 0 J F M A M J
July 89 - June 91