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Road Survey MethodIn order to evaluate the characteristics and extent of
road
freight traffic on the provincial roads and national
routes
within and through KwaZulu-Natal, a comprehensive
survey
of major freight routes was performed. Three sources of
traffic count information were utilised, namely:
- For national routes: Electronic count information as
produced by SANRAL. These are normally 12 to 24 months in
arrears, with the current available stats being for 2.
- For provincial routes: Electronic count information as
produced by the Provincial Roads Section. Some of these
counts can be dated up to 5 years in arrears.
- For national and provincial routes a current 12 to 24
hour visual survey is also undertaken.
The technique requires trained surveyors to position
themselves at selected strategic points and to record in a
pro forma the relevant characteristics of each freight
vehicle that passes. The survey is done in both directions
on the road for a period of 12 to 24 hours and the
results are punched into a database programme for
analysis.
The results of the surveys are retrieved from the database
and converted into spreadsheet tables, to permit
manipulation and analysis of the parameters of interest.
From the data derived from each checkpoint (survey
location), a set of 8 standardised tables is created, from
the sample of traffic recorded. The information is
extrapolated to annual totals for each parameter, to
provide an overall estimate of the characteristics of the
freight vehicle movements by road at that survey point.
The direction of traffic is recorded as North-bound/South-
bound or East-bound/West-bound as appropriate. The aspects that are analysed for each checkpoint are:
1. Proportions of Vehicles by Vehicle Groups
(configuration)
2. Proportions of Vehicles by Vehicle Types(description of
vehicle)
3. Freight Vehicle Traffic Flow by Direction
4. Commodity Proportions by Vehicle Numbers and Estimated
Tonnages
5. Estimated Total Annual Vehicles by Vehicle Group and
Commodity (where identifiable)
6. Estimated Total Annual Tonnage by Vehicle Group and
Commodity
7. Container Proportions by Vehicle Numbers and TEU Count
(number and category)
8. Estimated Total Annual Tonnage by Vehicle Group and
Dangerous Goods
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