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One of the problems in any rural landscape is the availability of services to the local population. These may be schools, health clinics, post offices, telecommunications, shops and any other public or private service. In urban areas these are nearly always within easy walking distance and access to them is only restricted by cost and the ability to pay.
In rural areas, almost by definition, access to services is also restricted by the remoteness of their location. Access is often measured by quoting straight line distances from services to potential users. In the UK for example, access to broadband internet connections has for some time been restricted to households within a 5km radius of a telephone exchange, which has excluded large areas of the rural countryside. Figure 1 shows how long it would take to travel to schools in a region, if it was possible to travel directly to them in a straight line at a steady speed of 30 kph.
Figure 1 Straight line times of travel to schools in an area, assuming a steady speed of 30 kph
In reality it is impossible to travel like this. Travel is usually confined to roads or tracks, and speed is anything but constant. In poor areas, travel may have to be on foot, or restricted to poor quality public transport network. The important measure of remoteness from a service is not the physical distance to it, but the time it takes to reach it. A hospital which is within sight on the far bank of a dangerous river is far more inaccessible than one 10km away on the same side. It will also take far longer to travel 5km on a rough dirt road than 20km on a paved highway. It takes longer to walk than to drive. Access to services in the rural environment is restricted both by cost and by accessibility travel times. A much more accurate picture of accessibility mapping is given in figure 2, showing the shortest times to travel to a school taking these factors into account.
Figure 2 Shortest travel times to a school allowing for road networks and varying speeds of transport
This case study sets out to describe how these travel times as shown in figure 2, may be modelled in a geographical information system (GIS) to produce accessibility maps as measures of rural service deprivation.