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GENERIC STEP-BY-STEP APPROACH STEP THREE

There are various optional approaches to conducting

accessibility modelling

Some methods are fairly quick and easy to follow while others are much more comprehensive and could
possibly require the use of sophisticated GIS-based analysis software. Several commercial GIS software
packages have advanced spatial modelling capabilities. There are also online tools that can assist you
to upload and visualize data, to conduct basic spatial analysis and to create maps and reports.

GIS-based accessibility modelling is a fairly complex method for conducting access studies and an
overview is provided in this chapter of the Guideline. Such modelling can provide detailed and accurate
spatial information that can assist you in your planning, depending on the completeness and quality of
your spatial datasets.

Simpler methods to determine the most optimum location for service points include, among others,
visualisation approaches and analysis with the aid of GIS software. Both make use of Google Earth, which
is readily available and fairly easy to use, to view the results of the analysis.

Google Earth contains satellite imagery that enables one to visualize the distribution of service points in
relation to the location and concentration of human settlements and existing infrastructure such as roads.

Annexure 2 of this Guideline provides an overview of how to apply some of the simpler methods.

This chapter provides guidelines only and these
should not be interpreted and applied rigidly

How to conduct a GIS-based accessibility analysis

There are six generic activities that you can consider in conducting an accessibility study (see Figure 17).
It might not be necessary for you to follow the same sequence, some of them can be done concurrently
and some might not be necessary considering the requirements and context of your study.

1 2 3 4 5 6
Determine
Determine Plan the Identify Prepare Determine optimum
department’s accessibility and weight the current levels provision of
accessibility study the factors to spatial of accessibility sites for
study needs consider in the data of service
study points services
points

Figure 17: The six generic activities in conducting an accessibility study

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