This book deals with appropriate methodologies for measuring traffic concentration and Level-of-Service (Los) of roads. The LoS of roads is quantified using speed-flow curves taking traffic density as the guiding factor. Later, a better measure to represent traffic concentration, named, ‘Occupancy'', was proposed. However, this measure is not appropriate for heterogeneous traffic conditions such as the one prevailing on the roads of developing countries. Hence, a new measure, named, ‘Area-Occupancy'', is proposed here. It has also been found that the proposed measure can be applied to homogeneous traffic conditions also. Hence, the proposed measure of traffic concentration will have universal application. Based on the new measure (area-occupancy), LoS criteria for roads carrying heterogeneous traffic were then developed and the various level-of-service boundaries were delineated. This book, we hope, will be a good reference for both academics and practicing professionals working in the area of Traffic Engineering.