Atmosphere Theme Report

Australia State of the Environment Report 2001 (Theme Report)
Lead Author: Dr Peter Manins, Environmental Consulting and Research Unit, CSIRO Atmospheric Research, Authors
Published by CSIRO on behalf of the Department of the Environment and Heritage, 2001
ISBN 0 643 06746 9

Urban Air Quality (continued)

Indicators of policy response (continued)

Motor vehicle usage [A Indicator 3.17]

  • Implications
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    The increase in registered Australian motor vehicles per thousand persons from 1982 to 1998 are lower than the 1990 car ownership figures for the USA (604 cars per 1000 people) and Canada (524), but exceed the numbers for Europe (392) and Asia (109) (Figure 120) (Newman & Kenworthy 1999).

    Figure 120: Registered Australian motor vehicles (cars, trucks and motorcycles) per thousand persons.

     Registered Australian motor vehicles (cars, trucks and motorcycles) per thousand persons

    Source: ABS (1997) and (2000a)

    A breakdown of the number of registered Australian motor vehicles in terms of vehicle type and State (Table 27) shows that Victoria and New South Wales dominate vehicle numbers, being the most populous.

    Table 27: Numbers of registered motor vehicles as at July 1998
    Type of vehicles NSW Vic. Qld SA WA Tas. NT ACT Australia
    Passenger vehicles 2 866 875 2 583 822 1 604 424 824 684 950 776 253 251 64 932 166 204 9 314 968
    Light commercial 434 037 360 037 339 925 109 766 189 593 54 342 24 622 16 371 1 528 693
    Rigid trucks 99 282 84 643 68 885 25 610 43 468 10 791 3797 2376 338 852
    Articulated trucks 15 205 16 946 11 775 5 537 6 778 1 457 822 274 58 794
    Other trucks 2 847 5 390 3 073 2 218 2 733 1 014 198 124 17 597
    Buses 15 608 11 175 11 003 3 558 7 022 1 846 2167 881 53 260
    Motorcycles 78 654 77 551 67 217 28 134 39 311 7 079 3579 5806 307 331
    Total 3 512 508 3 139 564 2 106 302 999 507 1 239 681 329 780 64 932 166 204 11 619 495

    Source: ABS (2000b).

    From 1982 to 1995, the age of the vehicle fleet increased from 7.5 years to 10.5 years, respectively. In 1998, the average Australian passenger car travelled 14 400 km (range, ACT 15 800 km to Tasmania 13 300 km). By contrast, articulated trucks covered an average distance of 92 100 km.

    Table 28 demonstrates the growth in the number of passenger vehicles in Australia, both in absolute terms and in terms of the number of vehicles per head of population, as well as the increase in the total distance driven by passenger vehicles.

    Table 28: Growth in Australian passenger car numbers and distance travelled by cars.
      Cars (thousands) Cars (per thousand people) Vehicle-kilometres travelled (billions of km)
    1979 5 652A 389.3B 84.8C
    1982 6 290A 415.6B 96.1C
    1985 6 926A 438.6B 106.6C
    1988 7 381A 446.8B 116.6C
    1991 8 012A 463.6B 114.3C
    1995 8 628D 478.8D 113.0C
    1998 9 315C 496.8E 134.3C

    A BTCE (1996: Table I.1, p. 331).
    B BTCE (1996: Table II.5, p. 356);
    C ABS (February 2000b): Table A3, p. 24).
    D ABS (1997: Table 1.4, p. 9).
    E ABS (2000a, p. 77).

    Figure 121 provides a breakdown of the distances travelled by cars in 1995 by state.

    Figure 121: Total distance travelled in 1998 (in million km) by passenger vehicles in Australia.

     Total distance travelled in 1998 (in million km) by passenger vehicles in Australia

    Source: ABS (2000b)

    Implications

    The most worrying trend in the motor vehicle data is the continued rise in motor vehicle ownership. Not only is Australia becoming more populous, but Australians are owning more motor vehicles. There appears a very slight decline in the distance travelled by each vehicle (Table 28, from 15 100 km in 1979 to 14 400 km in 1998) but after the recession induced slowdown from 1988 to 1995, the growth in the total number of vehicle-kilometres travelled has continued. Beer (1995) showed that if ADR37/01 had not been introduced, then the growth in vehicle kilometres travelled would have negated the benefits of ADR37 by 2011. The continued growth in vehicle-kilometres travelled implies that similar problems would eventually affect ADR37/01. Fortunately, the stricter emission limits that will be introduced together with the National Fuel Quality Act 2000 will continue to allow improvements in urban air quality. Unless some means can be found to reduce urban vehicle-kilometres travelled, stricter vehicle emission controls will have to be applied.

    Road Tunnels

    Both Sydney and Melbourne are developing networks of road tunnels that are of sufficient length that ventilation systems need to be installed to remove the air pollutants emitted by the motor vehicles inside the tunnel. There are two important considerations:

    • inside the tunnel, drivers and their passengers must not be exposed to harmful levels of pollutants
    • emissions of polluted air from inside the tunnel must not expose the ambient environment to harmful levels of pollutants.

    The atmosphere within a tunnel is dominated by vehicular tailpipe emissions. Duffy and Nelson (1996) examined the hydrocarbon species within the Sydney Harbour Tunnel (see table). Air in the tunnel is 30 times the European Community long-term goal of 1.5 ppb as an annual average, and nine times the current UK standard of 5 ppb.

    Hydrocarbon species within the air of the Sydney Harbour Tunnel
    Compound Mean concentration (ppb) Standard deviation (ppb)
    Ethylene 150.3 50.4
    Hexane 12.6 4.1
    Benzene 45.4 11.4
    Toluene 68.6 17.8
    Ethylbenzene 8.6 2.3
    p- and m-Xylene 31.3 9.6
    o-Xylene 11.7 2.9

    Source: Duffy and Nelson (1996).

    There is considerable debate as to the effectiveness of tunnel air particle filtering, whereas no gaseous air cleaning systems were scheduled to become operational towards the latter part of 2000 (Committee on Road Tunnels 1995; Dix 2000).

    The CityLink vent stacks in Melbourne aroused vigorous community debate (Kuchinke 2000). As a result, the Victorian EPA makes the vent stack data available for the previous 24 hours (http://www.epa.vic.gov.au/air/CityLink/ ) for the pollutants carbon monoxide, nitrogen dioxide, PM10 and PM2.5. The PM2.5 emissions (in kg/h) from one of the CityLink tunnel vents during 6-7 November 2000 were compared with the EPA licence limit of 1.40 kg/h for that vent stack (see figure 119). The EPA also provides online ambient air quality data in the local area of the stacks (see data for Burnley Street and Grant Street at http://www.epa.vic.gov.au/Air/Bulletins/aqbhour.asp ).

    PM2.5 Emissions

    Figure 119: Recorded emissions (kg/h) of PM2.5 from the Melbourne CityLink Domain Tunnel vent stack on 6-7 November 2000.

     Recorded emissions (kg/h) of PM2.5 from the Melbourne CityLink Domain Tunnel vent stack on 6-7 November 2000

    Source: Source: EPAV (2000c)

    International comparisons of pollutant concentrations

    Australian cities have good air quality when compared with some other cities, as shown in the following figures.

    Figure 122: Concentrations of ozone and PM10 in selected cities in 1995.
    Maximum one-hour ozone (upper figure) and annual average PM10 (lower figure).

     Concentrations of ozone and PM10 in selected cities in 1995

    Source: EPAV (2000b)

    Figure 123: Concentrations in selected cities of PM10 and nitrogen dioxide in 1995.
    Maximum 24-hour PM10 (upper figure) and annual average NO 2 (lower figure).

     Concentrations in selected cities of PM10 and nitrogen dioxide in 1995

    Source: EPAV (2000b)

    Figure 124: Concentrations of carbon monoxide in selected cities.
    Maximum one-hour CO in 1995 (upper figure) and maximum eight-hour CO in 1994 (lower figure).

     Concentrations of carbon monoxide in selected cities

    Source: EPAV (2000b)