The thickness designs in this chapter are based on LR1132 (Powell et al., 1984)
for flexible pavements and RR87 (Mayhew & Harding, 1987) for rigid construction. However, these basic designs are modified and updated based on later
research as detailed in HD 26/01 (DoT, 2001). The pavement thickness design
methodologies for the two different categories of pavement type are treated
separately below