Alcohol-Involved Pedestrians: The Australian Experience

OT Holubowycz

Department of Orthopaedics and Trauma, Royal Adelaide Hospital, North Tce, Adelaide 5000, Australia

ABSTRACT

Australian studies of alcohol involvement in pedestrian crashes are reviewed. The paper tabulates the results of these studies with respect to distribution of blood alcohol concentration (BAC), age and sex of intoxicated pedestrians, relationship between age and BAC among both males and females, time of day and day of week of crashes involving intoxicated pedestrians, pedestrian movement and pre-crash drinking patterns.

Overall only seven studies were identified. These indicated that 20-30% of pedestrian casualties had a BAC in excess of 150 mg/dL, with alcohol involvement being greater among fatalities. Few of the seven studies presented results pertaining to the other factors listed above. Those that did found that males comprised 60-70% of casualties with a known BAC and 80-90% of those with a BAC exceeding 150 mg/dL. Crashes occurring at night or on weekends were most likely to involve intoxicated pedestrians. Intoxicated pedestrians were hit most commonly as they crossed a road some distance from a traffic control; in those instances where the site had a traffic control, it was rarely used correctly. The one study that reported pre-crash drinking behaviour of intoxicated pedestrians found that about two-thirds had been drinking beer and about one-half had been drinking in a hotel.

The paper concludes that knowledge of the characteristics of alcohol-related pedestrian crashes in Australia is inadequate; recommendations are made to address these inadequacies.

INTRODUCTION

Pedestrians constitute a significant proportion of crash-related deaths and injuries in Australia. Police data indicate that 419 pedestrians were killed in 1990 and 3,283 were hospitalized, accounting for 18.0% and 13.1% of crash-related deaths and hospitalizations respectively (FORS, 1993). Pedestrian fatality rates for 1990 were 2.5 per 100,000 population in Australia, 2.6 in the USA, 2.2 in Canada and 3.1 in the UK (FORS, 1991; Economic Commission for Europe, 1992).

Intoxication among pedestrians has long been recognized as a risk factor in pedestrian crashes (eg Haddon et al., 1961; Honkanen et al., 1976; Struik & Rogerson, 1988). Indeed, comparisons of the extent of alcohol involvement among fatally injured pedestrians, drivers, passengers and motorcycle riders showed that alcohol involvement, particularly at the higher levels of BAC, was most prevalent among pedestrians (Holubowycz, in press). Recent studies both in Australia (Holubowycz, in press) and the USA (Centers for Disease Control, 1993) indicate that although the numbers and rates of adult pedestrian fatalities have decreased over the last decade, the significant decline in the extent of alcohol involvement observed among fatally injured drivers has not been evident among fatally injured pedestrians.

ALCOHOL INVOLVEMENT IN PEDESTRIAN CRASHES IN AUSTRALIA

There are few published studies of alcohol involvement among pedestrians in Australia; these are summarized in Table 1. These studies, however, provide little information on factors other than the distribution of BAC; the BAC results are summarized in Table 2.

Table 1
Description of Australian Studies on Alcohol Involvement among Pedestrians

Table 2
Distribution of BAC among Pedestrian Casualties

* BAC range: 1-149 mg/dl

** BAC range: >=150

*** BAC range: 0-10

**** BAC range: >10-150

Demographic Characteristics of Intoxicated Pedestrians

Few studies provide information on the demographic characteristics of intoxicated pedestrians. The available data on sex are shown in Table 3, on age in Table 4 and on the relationship between age and sex in Tables 5 and 6 for males and females, respectively.

Table 3
Sex of Intoxicated Pedestrians

Table 4
Age of Intoxicated Pedestrians

* Age categories of: 20-29, 30-39, 40-49,50-59, 60-69, 70-79

Table 5
Relationship between Age and Blood Alcohol Concentration among Males

* Age categories of: 20-39, 40-59, 60-79

Table 6
Relationship between Age and Blood Alcohol Concentration among Females

* Age categories of: 20-39, 40-59, 60-79

Time of Day and Day of Week of Crashes Involving Intoxicated Pedestrians

Table 7
Time of Day and Day of Week of Crashes Involving Intoxicated Pedestrians

Pedestrian Movement in Crashes Involving Intoxicated Pedestrians

The movements of intoxicated pedestrians within the road environment have not been commonly documented; the findings are presented in Table 8 below.

Table 8
Pedestrian Movement in Crashes Involving Intoxicated Pedestrians

Pre-Crash Drinking Patterns of Intoxicated Pedestrians

Only two studies have documented the drinking context of intoxicated pedestrians prior to their crash involvement, the findings of which are shown in Table 9 below.

Table 9
Pre-Crash Drinking Patterns of Intoxicated Pedestrians (if known)

Other Australian Studies

A number of other reports have included some data on pedestrian alcohol involvement, although these have been either incomplete or reported in more detail elsewhere (eg Aylward & O'Connor, 1988; Roads and Traffic Authority, 1994; Road Accident Research Unit, 1978).

LEGISLATION GOVERNING PEDESTRIAN BLOOD ALCOHOL SAMPLES

Table 10 below is taken from O'Connor and Trembath (1995) and shows the legislative requirements for the taking of blood samples for blood alcohol analysis from individuals presenting at hospital emergency departments following involvement in a road crash.

Table 10
Legislative Requirements for the Taking of Blood from Road Trauma Victims for Road Trauma Victims Attending or Admitted to Hospital (from O'Connor & Trembath, 1995)

(a) - Legislation for mandatory blood sampling of road trauma victims was passed through the Queensland Parliament in 1974 but was not proclaimed.

1 - In Victoria the legislation is worded to allow medical staff to take a blood sample for alcohol analysis under the specified conditions. There is an agreed code of practice whereby hospital staff take blood samples for alcohol analysis from all vehicle controllers subject to waiver conditions however the taking of blood is not mandatory under the legislation.

2 - In New south Wales blood is also taken from pedestrians.

3 - Blood sample is taken if patient is unable to give consent ie unconscious.

4 - Blood sampling of pedestrians and bicyclists may be undertaken over agreed time periods for the purposes of devising and evaluating programs.

As seen in the table only three states/territories, namely New South Wales, South Australia and the Northern Territory, have legislation allowing the mandatory taking of blood samples for blood alcohol analysis from injured pedestrians who present to hospital (subject to the waivers noted in the table). However, it is worth noting that the BACs of seriously injured (ie admitted to hospital) pedestrians are not reported in the routine annual crash reports of these three states, even though the data are presumed to be available. FORS (1993) reported that Australia wide police data on hospitalised (ie presumed admitted) pedestrians indicated that BAC was unknown for 57.2% of pedestrians aged 16 years or older.

According to O'Connor and Trembath (1995), for fatal cases, the coroner can be advised that a sample for blood alcohol analysis should be taken but it is then up to the coroner to request that this is done. The rate at which pedestrian fatalities are tested varies between states. For example, for those states where BAC data have recently been reported for a longer period of time, 52% of pedestrian fatalities of all ages were tested over the period 1986-1993 in Queensland (Fraine, 1994), BACs were known for 92% of pedestrian fatalities aged 16 or over in South Australia from 1981 to 1992 (Holubowycz, in press) and for 75% of pedestrian fatalities from 1983 to 1993 in Victoria (Vic Roads, 1994). It should also be noted that because some pedestrians are likely to die after admission to hospital, the rates of known BACs are likely to be higher in those states with mandatory blood alcohol testing in hospitals.

Haworth & Rechnitzer (1993) reported that BAC data were missing for 55% of 7498 persons included in the 1988 FORS Fatality File and that missing data were more likely for non-drivers/riders and for those not severely injured. They also noted that the percentage of missing data varied substantively between states. Unfortunately their report did not provide any straightforward data on alcohol involvement in pedestrian crashes, as alcohol crashes were defined according to alcohol being coded as the first or second most important contributing factor to the crash and according to the maximum BAC of persons responsible for that crash (ie >150 or 50-150 mg/dl).

CONCLUSIONS

Extent of Alcohol Involvement

The Australian studies indicate that 20-30% of pedestrian casualties have a BAC in excess of 150 mg/dl. These findings support the results of case-control studies which have shown that alcohol plays a signifcant role in the aetiology of pedestrian crashes. The extent of alcohol involvement is highest among fatalities.

Age and Sex of Pedestrian Casualties

The few studies that have reported the sex of pedestrian casualties have indicated that males comprise 60-70% of casualties with a known BAC, and 80-90% of casualties with a BAC in excess of 150 mg/dl.

The available data on age and BAC among males shows that in most instances at least one-third of every age group with the exception of the elderly had a BAC in excess of 150 mg/dl. However, the results of the studies did not suggest that any particular age group was consistently more likely to show an elevated level of alcohol involvement. The data on females is less conclusive given the relatively small numbers of casualties.

Time of Day and Day of Week

Alcohol involvement appears to be highest at night and on weekends.

Pedestrian Movement

Only three studies examined pedestrian movement in relation to BAC. Crashes involving intoxicated pedestrians predominantly occurred whilst crossing roads at a site some distance from a traffic control. However, if the site had some form of traffic control, this was rarely used correctly.

There was little agreement with respect to the side of the road on which crashes involving intoxicated pedestrians were most likely to occur: one study reported equal representation between near and far-sided crashes, one reported a much higher prevalence of the former and the third reported a somewhat higher prevalence of the latter.

Drinking Behaviour Prior to Crash Involvement

Only one study examined where, what and with whom the intoxicated pedestrians had been drinking prior to their crash. About two-thirds had been drinking beer, a similar proportion had been drinking with family and/or friends and just over one-half had been drinking in a hotel.

RECOMMENDATIONS

The relatively low number of studies and, in particular, recent studies, coupled with the relatively high rates of unknown BACs in most of the studies, limit our knowledge of the true extent of alcohol involvement among pedestrian casualties.

Our knowledge of the characteristics of alcohol-related pedestrian crashes is totally inadequate. This is of major concern because the successful design and implementation of countermeasures requires a sound knowledge of such characteristics.

To address these inadequacies, this report makes the following recommendations:

Recommendation 1

That selected samples of crash-involved pedestrians are interviewed to ascertain the following characteristics:

• age and sex
• pre-crash drinking behaviour
  what/where/with whom was pedestrian drinking?
• usual drinking pattern
  quantity and frequency of drinking; usual beverage type; drinking locations; drinking company
• usual drug use
  frequency of use of eg cannabis, amphetamines (eg speed), sedatives
• pre-crash drug use
  use of eg cannabis, amphetamines (eg speed), sedatives
• intended transportation mode of pedestrian
  how did pedestrian arrive at the last destination prior to the crash and how did the pedestrian intend to reach the next destination?
• pedestrian behaviour at time of crash
  location of crash (eg midblock etc), proximity to traffic controls, pedestrian movement, lighting
• exact location of crash with respect to specific roads
• time of day and day of week of crash

These samples should be derived from:

(a) prospective studies of crash-involved pedestrians admitted to hospital

It is recommended that samples be selected on the basis of hospital. Although admissions to any one hospital are unlikely to be representative of all serious pedestrian casualties, the ease of accessing such a sample probably justifies the resulting selection bias, especially as the nature of this bias can be estimated.

(b) retrospective follow-up studies of crash-involved pedestrians

Pedestrians could be identified retrospectively from existing site-specific studies of pedestrian crashes such as that of Toorak Road, South Yarra (Diamantopoulou & Corben, 1994). No alcohol data are available for that study although the crash characteristics suggest a high level of alcohol involvement. Interviewing these pedestrians about their drinking behaviour prior to crash involvement would provide a valuable supplement to the data already available from that study.

Recommendation 2

That each state routinely collects and reports the following data on fatally and seriously injured (ie admitted to hospital) pedestrians:

• blood alcohol concentration (for all pedestrians aged eg 16 years or older)
• age
• sex
• time of day
• day of week
• location with respect to specific roads

Recommendation 3

That all Australian states adopt a uniform method of reporting alcohol use among killed and injured road users including pedestrians, particularly with respect to BAC categories reported (eg zero, 1-49, 50-79, 80-149, 150-249, >=250 mg/dl) and the ages of pedestrians for whom BACs are reported (eg >=15 years old).

It is recommended that tables be of the following format:

BAC distribution of fatally injured pedestrians aged >=15 yo, by sex

* Pedestrians with an unknown BAC as percentage of all pedestrians aged >=15 yo.

The important feature of the above table is the reporting of the number and percentage of pedestrians with unknown BACs within the age group for which BAC should be reported, as well as the number below that age limit.

Recommendation 4

That individual sites at which more than a predetermined number of pedestrian crashes occur over a certain period of time are subjected to a safety audit to determine whether specific environmental modifications would reduce crash numbers.

Recommendation 5

That in selected hospitals around Australia, data on emergency room attendances (including admissions) resulting from vehicular trauma are linked with police crash reports and blood alcohol data to enable the monitoring of trends in pedestrian crash patterns.

Recommendation 6

That funding for the implementation of countermeasures is dependent on the inclusion of an evaluation of outcome.

ACKNOWLEDGEMENTS

This paper was prepared as part of the Intoxicated Pedestrian Project funded by Austroads; the assistance of Rob Klein, John Collis and Steve Brown is gratefully acknowledged. The views expressed are those of the author and do not necessarily represent those of Austroads.

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