The real-time railway traffic management problem (rtRTMP) is the problem of solving time-overlapping conflicting track requests generated by disturbances during the normal course of daily operations. The size of an instance of the problem and the time required to solve it are particularly affected by the number of routing alternatives available to each train. The real-time train routing selection problem (rtTRSP) chooses a feasible routing subset for each train to use as input for the real-time railway traffic management problem. In particular, the validity of the problem and the impact of its solution have been analyzed in the literature. The analysis has been performed by using a specific mixed-integer linear programming model and the RECIFE-MILP solution approach for the rtRTMP. This paper generalizes such analysis by considering also a different model, objective function and solution approach for the rtRTMP. We consider the decision support system AGLIBRARY which solves an alternative graph model of the problem to minimize the maximum consecutive delay. The aim is to assess whether the selection of a subset of routings brings advantages for different solvers. We analyze how changes in the rtRTMP model have to be reflected in the rtTRSP and, if so, which modifications are required. The computational analysis is performed on two French infrastructures: the line around the city of Rouen and the Lille terminal station area. The analysis shows that solving the rtTRSP helps both solvers significantly, even if they are based on different models and algorithms.