| dc.description.abstract | The road network is the backbone of transport systems in Uganda. Road transport is the most
dominant mode of transport and it accounts for over 90% of the cargo freight and passenger
movement. The entire road network in Uganda totals to 144,785 kmof this only5,100 km(4%)
ispaved, the rest being gravel or earth roads. Kampala(the study area) has an estimated road
network of 2,110 km of which only 578 km is paved.One of thechallenges faced by agencies
responsible for the development, construction, and maintenance of these roads is axle loading
control partly due to the constantly increasing traffic volumes (estimated at 6%), which causes
the actual axle loading imposed on the pavementstovary from the design axle loading. When
these roads are exposed to destructiveclimateand traffic loading, the pavements deteriorate
faster resulting in poor road conditions duringthe time in which theroadis in service, especially
when maintenance interventions are not duly scheduled. This research was conducted to
determine the effect of traffic volume and environmental factors on road deterioration in order to
determine at what point in time a pavement should be maintained. Traffic volumes were
determined by carrying out Manual Classified Traffic Counts and the volume was converted to
axle loadingusing an equation stated inRoad Design Manual Vol III, Part 1 for Flexible
Pavements. Environmental conditions were incorporated into the research by using an
environmental coefficient that was given in the HDM–4. Road conditions were estimated using
a Road Visual Condition Assessment from the Ministry of Works and Transport. It was observed
that road conditions deteriorate more under the combined effect of environmental factors and
increase in axle loading that is to say, for Old Kira road when axle loading increases from 0.69
MESAL/lane/year to 3.00 MESAL/lane/year, the IRI will increase from 7.9 to 9 that isfrom fair
road conditions to poor road conditions which will take approximately 2 years and for Kyebando
– Kisalosalo road, when axle loading increases from 0.45 MESAL/lane/year to 3.85
MESAL/lane/year the IRI will increase from 6.6 to 9 which is from a fair to a poor road
condition which will happen approximately in 4 years. | en_US |
