  In this work, we show the importance of considering a city's shape, as much
as its population density figures, in urban transport planning. We consider in
particular cities that are circular (the most common shape) compared to those
that are rectangular: For the latter case we show greater utility for a single
line light rail/tram system. We introduce the new concepts of Infeasible
Regions and Infeasibility Factors, and show how to calculate them numerically
and (in some cases) analytically. A particular case study is presented for
Galway City.
