Rationality of route layouts as a quality indicator of urban road networks

A number of measuring scales have been developed for the purpose of determining the acceptability levels of travel routes from the geometry point of view for urban networks. These scales have been studied under four headings: Distance as the Crow Flies, Average Speed, Alternative Routes and Angular Deflection. Besides, in order to be able to evaluate all these scales simultaneously, a common scale has been introduced. This, therefore, will enable researchers and practitioners to compare the road networks of various cities with varying size and geometry. These scales are then applied on a number of different cities around the world, and the road networks belonging to these cities are ranked according to the rationality criteria introduced.