Extensive work exists on regular rail network planning;​ however, few studies exist on the planning and design of ring-radial rail transit systems. With more ring transit lines being planned and built in Asia, Europe and the America’s, a detailed study on ring transit lines is timely. This thesis is based on idealizing transit network in perfect ring-radial transit lines. An analytical model using the continuum approximation approach is first introduced to find the optimal number of radial lines considering a city with a radio-centric street network. An approximate analytical model for ring-radial rail network planning is then introduced allowing analysis of the feasibility and optimal alignment of a ring transit line in a city. The city of Calgary‘s light rail transit network and Shanghai metro network are used to illustrate the applicability and transferability of the model. The model is then extended to allow simultaneous consideration of radial and ring lines and analyzing a transit network with partial ring and radial lines. This extension allows a more realistic idealization and analysis of rail transit networks. A benchmark analysis of cities with ring transit lines is used to identify prominent types of lines in idealized ring-radial transit networks. The cities are then assessed based on their unique network patterns using identical model inputs such as length of rail transit network and trip distribution patterns. This thesis provides a decision support tool for transit planners to compare the performance of different rail transit network extension alternatives for long-term rail transit planning. It can also be used for cost-benefit analysis to compare total generalized passenger cost savings versus the cost of network extension. Unlike simulations and agent-based models, this model is shown to be easily transferable to many ring-radial transit networks. Therefore, with a daily OD trip matrix and transit network supply characteristics and parameters as input, the model can be implemented for many radio-centric cities. The benchmark analysis using the combined universal ring-radial rail transit network model is a mathematically sound platform to compare different rail transit networks and propose the best examples of rail network topologies.