Sunday, April 21, 2024

Botswana roads among most circuitous in Africa

The old Mahalapye-Kalamare gravel road was long and straight and disappeared into the horizon. However, the new tarred road took a different character: from Mahalapye, it goes to Bonwapitse, then winds its way to Mmutlane before terminating in Kalamare.

Building roads in this manner is in line with a policy that was developed during the administration of President Sir Ketumile Masire. In terms of this policy, a road has to pass through villages that are within 10 kilometres, don’t themselves have tarred roads and there is always an internal road terminates at the kgotla. With cost, lay of land, safety and physical barriers in mind, there would also be considerations of what routes are the most suitable. For all its benefits, this policy makes Botswana roads one of the most circuitous in Africa in terms of new metrics developed for road networks of African countries.

The metrics in question use two measures (circuitousness ratio and distance ratio) which rely on the relationship between the geographic distance between two urban centres and the actual travel distance along primary roads between places. These metrics were developed by the OECD, the United Nations and the African Development Bank.

The circuitousness ratio is a measure of whether roads in a country take a direct path or if they make detours to avoid natural obstacles such as rivers or mountains. It is applied to two urban areas that are directly connected by a road. This ratio increases the more a road deviates from a straight line and the travel distance between the urban areas increases. By computing the ratio for all pairs within a country that are directly connected by a road, it is possible to calculate the average circuitousness ratio by country.

The distance ratio is a similar ratio that also takes into account that many urban areas are not connected by a direct road. Instead of going directly from one area to another, detours via other areas are needed. The distance ratio takes this into account by calculating the ratio of the road distance relative to the geographical distance for all urban areas within a country, whether or not they are connected by a direct road. The country average of this ratio is influenced by two factors, the circuitousness of the existing roads and the degree to which the road network requires detours via other urban areas instead of connecting place-pairs directly. Places located on a flat plain with no major obstacles between them are easier to connect by a direct road than cities separated by a mountain range.

Via this mathematical process, Botswana placed seventh from a total of 34 African countries. Some of Africa’s most developed countries, such as Algeria, Egypt and South Africa, have the lowest road-to-geographical-distance ratio, indicating that most of their urban areas are connected by direct road links.


Read this week's paper