17 
PRIVATE PRACTITIONER USAGES 
Much of the productive plotting (and orthophoto) work performed 
for several of the highway and railway authorities in Australia 
is entrusted to private practitioners equipped and staffed to 
offer relevant services to clients. These practitioners also of- 
fer such services to clients other than the State Road Authori- 
ties and it is believed that some Local Government Authorities 
in Australia avail themselves of such services. Some Australian 
photogrammetric practitioners also undertake work in various 
countries in South East Asia and in New Guinea. 
several major railway developments associated with minera] pro- 
jects have been designed from photogrammetric data provided by 
private practitioners. Few of these projects have led to the 
publication of relevant technical papers, but a paper dealing 
with the design and construction of the Greenvale Nickel Rail- 
way in north Queensland was presented to the 1975 Congress of 
the Institution of Surveyors, Australia, held in Perth in April 
1975, of which the authors were senior representatives of a 
firm of consulting engineers which has a photogrammetric estab- 
lishment. 
FUTURE TREND 
The pace of development of usage of photogrammetry for highway 
and railway design work in Australia has been and remains rather 
slower than the needs would seem to justify. However, both in 
New South Wales and in South Australia, progress has been and 
will continue to be made towards usage of digital photogrammet- 
ric data, both for digital mapping and for digital terrain model 
purposes. Interest is growing in the application of multi-spect- 
ral imagery to assist in the location of construction materials. 
It seems very likely that there will be trends towards the deve- 
lopment of multi-disciplinary teams concerned with studies of 
terrain form using digital data produced photogrammetr ically, 
for the purposes both of location optimisation and of detailed 
design. Such studies will extend to the assessment of earthwork 
volumes moved on major construction projects, to assist in pro- 
ject management. Other multi-disciplinary teams will be engaged 
on studies of the nature of the terrain, using data derived 
from remote sensing techniques. 
For the production of digital photogrammetric data the trend to- 
wards analytical instrumentation seems likely to be very approp- 
riate for highway authorities to follow, although analogue inst- 
rumentation currently available and installed may be expected 
to remain of value and in use for many years yet.