The sustainability of gravel roads as depicted by sub Saharan Africa's standard specifications and manuals for road works: Tanzania case study

Abstract

The sustainability of gravel roads depends, among other things, on the appropriate locally formulated manual and standard specification. These regulating documents should not only address how best these roads could be brought into being but also address the environmental and climatic issues affecting or affected by gravel roads. To achieve that goal, these manuals and standard specifications have to ensure that during their design life, the gravel roads constructed are in harmony with the environment. In that period, the gravel roads should contribute less to the pollution and degradation of the environment and climatic changes. This can be achieved through properly documented mitigation procedures embedded during gravel roads design and construction and also during routine and periodic maintenance. This paper reviews what is specified in the Tanzania's Pavements and Materials Design Manual (PMDM) and the Standard Specification for Road Works (SSRWs), in particular on environmental and climatic issues associated with the gravel roads construction and maintenance activities and mitigation measures adopted. The review results show that the Tanzania PMDM and SSRWs do not adequately address environment and climate issues affecting or being affected by gravel roads performance. This paper concludes by listing the appropriate measures expected to achieve gravel roads sustainability. © 2014 WIT Press.