Parts of the existing Ruhengeri to Gisenyi road in the North Western part of Rwanda winds along steep mountainous hillsides which stand at ~8,000 feet. The large number of trucks travelling to the Democratic Republic of Congo has resulted in the edge of the road falling away down the hillside. The project formed part of the African Development Bank and European Commission collaboration for Rwanda's transport improvement program, with this particular part of the project financed by the European Commission. Part of the large rehabilitation project to reconstruct and improve the general alignment and safety of the road, included a 350m section where a reinforced soil solution was adopted. The 70° steep reinforced soil slope raised to a maximum height of 8m. The use of reinforced soil allowed the road to be widened and the use of locally won fill from a local quarry to be used, thus negating the use of concrete structures or other expensive material solutions. Additionally, a vegetated slope face allowed the structure to blend in with the existing landscape.

This paper looks at the design methods used and also provides a photo chronological sequence to clearly demonstrate this type of construction. The paper also highlights some of the techniques that can result in high quality construction of reinforced soil structures.

This form of construction also provided a sustainable solution with respect to carbon footprint and the paper includes information on recent research undertaken on comparison of construction techniques with respect to carbon emissions and sustainable construction.