They are idiosyncratically written on a number of walls running along major highways as if an overzealous teacher is testing members of the public on basic arithmetic.
Most of the time, they are simple addition like 0+0641, which ideally should be very easy to calculate and provide an answer for, but people seem not to understand their meaning.
Speaking to Kenyans.co.ke, Civil Engineering Expert Cynthia Mukami Marangu explained that the unique numbers are known as Highway chainage which are emboldened on walls close to major highways.
"Highway chainage is a system of measuring distances along a highway. It is used by engineers, surveyors, and other professionals to locate specific features on a highway, such as bridges, culverts, and manholes.
"Chainage is measured in meters, and it is always positive. The starting point for chainage is the beginning of the highway, and the distance is measured in the direction of travel. For example, if a bridge is located 1,000 meters from the beginning of the highway, its chainage would be 1,000," Cynthia Mukami Marangu explained.
According to Mukami, a chainage is a useful tool for planning and construction projects on highways. It can be used to determine the cost of materials and labour, and it can also be used to coordinate the work of different contractors.
When the number states something like, (0+100), it means that [0] is the starting point plus 100 metres ahead, it offers a precise and accurate system of measurement.
"Highway chainage is a valuable tool for engineers, surveyors, and other professionals who work on highways in order to locate specific features on a highway and to plan and coordinate construction projects," Mukami stated.
Some of the limitations of using highway chainage include the fact that it is not always possible to measure the exact distance to a feature.
At the same time, the accuracy of chainage measurements can be affected by the terrain since chainage measurements can be difficult to make in areas with heavy vegetation.
The Kenyan highways system is a network of roads that connect the major cities and towns, it is managed by the Kenya National Highways Authority (KeNHA).
The Kenyan highways system is divided into three classes:
Class A highways are the most important highways in Kenya. They connect the major cities and towns and are used for long-distance travel.
Class B highways are less important than Class A highways, but they are still important for regional travel.
Class C highways are the least important highways in Kenya. They are used for local travel.
Some of the major highways in Kenya include Nairobi–Mombasa Highway, Nairobi–Nakuru–Eldoret Highway, Nairobi–Kisumu Highway, Mombasa–Malindi Highway and Mombasa–Uganda Highway.
Others include Lamu–Garissa Highway, Isiolo–Marsabit Highway and Wajir–Mandera Highway which are used to transport goods and people and promote tourism.
