The general research here introduced concerns the phenomenon of urban sprawl unfolding in the last century and defined as “the physical pattern of low- density settlement in urban areas”. The focus, as part of the more general research cited, is the relationship between sprawl and public transportation. The specific study here present is a possible approach to planning and managing policy responses to urban sprawl through the integration of consolidated settlement systems (with a view to their re-revitalization) with rail green public transportation in the framework of TOD (Transit-Oriented Development). A paramount issue emerges about sprawl: there are prototype case in which TOD and rail green public transportation help concentrate settlement instead of sprawl? No cases have been found. Instead the most recent literature recommends to perform new researches concerning solutions through real world applications, given the total shortage of case studies. The general research framework has been applied in a specific Case Study to support the community of Calabria, the southernmost Mediterranean region of mainland Italy in European Union, within the most urbanized sub-regional sub-area, in analyzing the rampant phenomenon of sprawl and, possibly, in addressing and mitigating it relying on TOD and rail green public transportation. In the Case Study of the present research there are three alternatives in sub regional public transportation: A1; A2; A3. A1 is the status quo. A2 is the upgrading of the railway which, although existing, is illogically neglected. A3 is an unexpected new project by the railway managing body for a new route in the south of the area completely away from the most important settlements and outside any transport or mobility or accessibility institutional public plan. The three alternatives were subjected to social discussions well as a qualitative evaluation by a panel of experts. The multiple criteria valuation approach resulted in a preference for Alternative A2 over Alternatives A1 and A3. The preferred Alternative A2 integrates perfectly with the existing settlement by responding to a fundamental criterion placed at the top of the valuation: integrating the urban railway directly into the existing consolidated inhabited centers. This preferable Alternative A2 has among its peculiar characteristics: – directly connects many of the settlements in the area; – can serve approximately MORE THAN 250,000 potential settled residents; – connects coast to coast the narrowest regional and national isthmus; – creates the fastest and shortest possible connection in the national territory between the two fundamental railway backbones Tyrrhenian (Palermo - Milan - Torino) and Ionian-Adriatic (Reggio Calabria - Venice); – thereby helping to connect two of the Trans European Network and pan-European train mega-corridors I (Palermo - Berlin) and VIII (Skopje - Varna). The A2 Alternative has the further distinctive feature of performing both local and supra-local dual service in a unified venue that is both train-tram and long-distance rail, in analogy with continental benchmarks and experiences, such as the German S-Bahn. Subsequently, in the Case Study, the costs of the Alternative A2 for the upgrading (and “modernization”) of the existing railway has an estimated cost of 168 million appraised by the research team with a detailed quantification, and subsequently, in de facto double-blind estimate, surprisingly confirmed by the railway managing body. According to the latest and most up-dated estimates by the same railway managing body, the completely new route project located far south of all the settlements, constituting the Alternative A3, would cost over 485 million, are reported. This is because all the areas have to be acquired and because the route crosses land with technical difficulties to be overcome by carrying out expensive works. In terms of costs, the preferred Alternative 2 seems to be the most balanced, much more even than the status quo Alternative 1 (do nothing). The latter only apparently has no big investment costs, unless ordinary maintenance. In fact it hides enormous private costs and implicit (and not immediately monetary) social suffering, due to: car commuting (un-pooled) of people; their monetizable travel times, enormous due to congestion; air pollution; accident risks; congestion in cities; high private personal costs of using the individual vehicle (car wear; fuel); parking cost and fine risk; etc.