Competitive transit network design in cities with radial street patterns

This paper presents a reformulation of the hybrid model developed by Daganzo (2010) to extend its applicability to a greater number of cities, especially those characterized by a radial street pattern. The new transit network structure is also composed of two types of schemes: radial/circular in the central area and hub and spoke in the periphery. This analytical model defines the optimal network layout through minimizing its objective function, which is composed of agency and user costs. Its decision variables are central area size, headway, line spacing, and stop spacing. In this reformulation, stops with single coverage, those only served by one line, are introduced in the hybrid model to improve spatial accessibility to avoid an increase in agency investment. This model is a tool to design competitive transit systems topologically characterized by simple schemes adapted to the urban structure and concentrated transit flows, and also operatively by high frequencies and speeds. Ultimately, all this allows for easy use and management of transit networks.