A Perspective into Development of Pavement Design Methods for Low Volume Roads: A Review

Abstract

The definition of low volume roads (LVRs) is not time static and it varies from place to place around the world. The importance of such roads for providing access, in connecting communities and link farms to markets is well appreciated worldwide. LVRs are credited as the direct source of social economic development in rural communities, growth, reduction of poverty and sustaining livelihood. Nevertheless, the LVR network is growing at an unsatisfactory rate especially in Sub-Saharan Africa. The slow rate in developing LVR network is attributed to the high cost of construction and maintenance. To the author’s perspective, research has a significant role in lowering both maintenance and construction costs and in turn realise a growth in the network size and adequacy. To demonstrate the importance of research in road development, a comparison has been made between the current and the previous pavement design methods for LVRs in Tanzania. The improvement so far has been in the determination of subgrade strength using the Dynamic Cone Penetration (DCP) method instead of the less accurate and more demanding California Bering Ratio (CBR) method; a simpler approach in estimating design traffic load that is also less conservative; encouraging the use of local natural materials which could be marginal for construction instead of the conventional but expensive crushed rock; and improvement in layer design which result to less pavement thickness. While all these improvements enhance saving in pavement cost, it is argued that further development is possible through research especially in local materials and procedures.