Alignment analysis of urban railways based on passenger travel demand

Planning of urban railways like Metro and especially Light Rail Transit often result in multiple alignment alternatives from where it can be difficult to select the best one. Travel demand is a good foundation for evaluating a railway alignment for its ability to attract passengers. Therefore, this article presents a computerised GIS based methodology that can be used as decision support for selecting the best alignment. The methodology calculates travel potential within defined buffers surrounding the alignment. The methodology has three different approaches depending on the desired level of detail: the simple but straight-forward to implement line potential approach that perform corridor analysis, the detailed catchment area analysis based on stops on the alignment and the refined service area analysis that uses search distances in street networks. All three approaches produce trustworthy results and can be applied as decision support in different stages of the urban railway alignment planning.