Flexible and Rigid pavements are the two main type of road pavements that are used the world over. In countries like India and other countries of the world as well, flexible pavements or bituminous pavements are used on majority of the roads because of their low initial cost, ease of construction and maintenance, and faster progress of the construction work. However, the maintenance cost of bituminous pavements is quite high. The total cost of construction and maintenance of rigid pavements or concrete pavements over their design life may be much less than bituminous roads for certain values of subgrade strength and design traffic. The conditions of subgrade strength and design traffic that will make a given type of pavement more economical are usually not well understood by the professionals. Designs and their cost estimation have been worked out in the book for a given road both for bituminous and concrete pavements for varying values of subgrade strength of CBR 4% to 10% and design traffic of 2 msa to 150 msa. Through these designs and cost estimations, the book brings forth the values of subgrade strength and design traffic that make a given type of pavement more economical. It is expected that the book will help the professionals in taking proper decision while deciding the type of pavement that is whether to provide a bituminous pavement or a concrete pavement.