By Mutabazi Sam Stewart
Uganda’s roads especially those in Kampala are falling apart. The rains have made the bad situation worse. Potholes which were small have instantly become wide and deep. Some roads have what can be termed as galleys because big chunks of road surfaces have been washed off creating big water logged ponds in the middle of the roads. Traffic jams have increased especially during peak hours because vehicles have to slow down as the approach such spots. Kampala Capital City Authority (KCCA) is overwhelmed by the magnitude of the problem as the routine maintenance works they had started on seems to have come to a naught. The patch work they had done on some roads has not been spared either. The heavy rains that Kampala has experienced have even left meteorology officials guessing and making predictions that have left the publish wondering whether to believe weather forecasts. It was reported last week that many roads were cut off leaving some residents in tears.
The public seems to have resigned to fate as far as bad roads in Kampala are concerned because they have become the norm. The worst case scenario of a typical road in dire disrepair can be found on Ntinda road after Nakawa junction lights on the corner near Transami Limited. On many occasions traffic has had to be diverted from this vital road because of the poor condition it is in. Trucks that deliver goods to nearby warehouses have to negotiate through an almost impassable road to access their businesses. Small cars have to literally move on their “bellies on this particular section”. The traffic police who usually control traffic at the nearby Spear Motors junction normally look on helplessly as jam builds up. This is just one case of the many problematic spots on our city roads.
Our roads will continue to deteriorate unless we embrace modern urban planning practices. The time of having narrow roads is long gone. Our road designers need to come to terms with this fact. As the city expands, so should the roads. This goes hand in hand with physical planning. Again, KCCA together with the district authorities that share a boarder with Kampala need to encourage commercial high-rise residential buildings to maximize space rather than the current craze of small individual housing units that are untenable. Kampala has too many roads to develop simply because residents are building everywhere and anyhow. Each person who builds a small personal residential house on a small piece of land expects to have private access in form of a road. Even provision of other services like water and electricity is quite difficult because of the small residential units that utility companies have to serve.
The other challenge we face is related to environmental problem that does not compliment bituminized road resilience. Uganda has weak soils which cannot support long term road pavement. Although Uganda has one of the best climatic conditions in the world that favours agricultural production and tourism, our soils are not the best when it comes to road development. The typical conditions do not favour permanent pavement strength and durability. In spite of the fact that our soils are weak, the material specifications and designs used on most of our roads use low volume seals which leads to fast deterioration. The high concentration of traffic in and around Kampala metropolitan area coupled with narrow roads means that road surfaces weaken faster for the reason that countless vehicle tyres trample on the same paving leading to pavement failure. Even where road bases and sub grades have been improved upon, they are continually eroded beginning from the sides of the road.
It is true that our road performance is structurally deficient but it is also true that our physical planners and road designers are hiding behind the excuse that wide roads are expensive to build. The narrow roads that characterize our fast expanding city can never be reinforced enough for the heavy rains that Uganda normally receives. Even though it is cheaper to construct the narrow roads in the short run, they are very expensive to maintain, at least to keep them pothole-free. The proposal by cabinet to extend the boundaries of Kampala to take over Wakiso, Mukono and Mpigi districts was commendable in my view and should therefore be vigorously pursued. Kampala is too crowded to have broad better roads.
**The writer is the Executive Director of Uganda Road Sector Support Initiative (URSS)
Congratulations...Very good article, you describe really good the dimension of the problem about the roads quality in Uganda and the expectatives for the population for residential buildings.
I think that you may review experiences in another countries with similar weather and soils same as uganda may be brasil I know that in peruvian jungle (next to the frontier with brasil) with a bad soil anda very cloudy time; the roads have a short resistance buit with similar caracteristic in Brasil the roadas are better than in Peru and long term in Brasil; i recomend to you that review the specification for that Brazilean roads or someone country similar with positives results.
About the residential buildings, I think that you need a program that build apartments with public or privates resources that finance it.
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The AASHO Road Test was a series of experiments carried out by the American Association of State Highway and Transportation Officials to determine how traffic contributed to the deterioration of highway pavements. Officially, the Road Test was "...to study the performance of pavement structures of known thickness under moving loads of known magnitude and frequency." This study, carried out in the late 1950s in Ottawa, Illinois, is frequently quoted as a primary source of experimental data when vehicle damage to highways is considered, for the purposes of road design, vehicle taxation and costing.
The road test consisted of six two-lane loops along the future alignment of Interstate 80. Each lane was subjected to repeated loading by a specific vehicle type and weight. The pavement structure within each loop was varied so that the interaction of vehicle loads and pavement structure could be investigated. "Satellite studies" were planned in other parts of the country so that climate and subgrade effects could be investigated, but were never carried out.
The results from the AASHO road test were used to develop a pavement design guide, first issued in 1961 as the "AASHO Interim Guide for the Design of Rigid and Flexible Pavements", with major updates issued in 1972 and 1993. The 1993 version is still in widespread use in the United States. A new guide, originally planned for release in 2002 but as yet still under development, would be the first AASHO pavement design guide not primarily based on the results of the AASHO road test.
The AASHO road test introduced many concepts in pavement engineering, including the load equivalency factor. Unsurprisingly, the heavier vehicles reduced the serviceability in a much shorter time than light vehicles, and the oft-quoted figure, called the Generalized Fourth Power Law, that damage caused by vehicles is 'related to the 4th power of their axle weight,' is derived from this. The other direct result of the tests were new quality assurance standards for road construction in the US, which are still in use today.
The road test used large road user panels to establish the "Present Serviceability Rating" (PSR) for each test section, as the test proceeded. Since panel ratings are expensive, a substitute key parameter "Present Serviceability Index" (PSI) was established. The PSI is based on data on the roads longitudinal roughness, patch work, rutting and cracking. Later studies have shown that PSI is mainly a fruit of unevenness, with a correlation of more than 90% between the two. Uneveness was measured with a mechanical profilograph, reporting a parameter called slope variance (SV). SV is the second spatial derivative of height. For a vehicle travelling at speed, SV is the exciting source to vertical acceleration; the second derivative in time domain of height. This makes very good sense, since 1 – 80 Hz acceleration is the parameter used when relating human exposure from vibration to perceived discomfort in the current ISO 2631-1 (1997) standard. Thus, SV is physically linked to ride quality.
While the study is now quite old, it is still frequently referenced, though critics point out that its data is only valid under the specific conditions of the test with regard to the time, place, environment, and material properties present during the test. Extrapolating the data to different situations has been 'problematic'. Other studies have attempted to refine the results, either through further empirical studies, or by developing mathematical models, with varying success. The AASHO study is still the most often quoted study on the subject however.