This study has investigated the effects various effects that driver behavior has on the analyses and simulations carried out by the Swedish Transport Administration. By making assumptions about train drivers' braking ability - which has been modelled by braking percentage and implementing these in the same analysis methods that the Swedish Transport Administration use - the effect of how different driving behaviours affect the results of these analyses can be assessed.  The analyses have been carried out on the Sundsvall–Umeå line: a section where ERTMS is already implemented. The following analyses have been performed in the Railsys tool: runtime analysis, headway analysis (how close two trains can drive after each other), and punctuality analysis. The result of the runtime analysis shows that the effect on runtime is not significant between different driver behaviors. However, there is a greater effect on the headway analysis; the results show that trains can drive significantly closer after each other on stretches where braking is common. The punctuality analysis shows little difference in punctuality. But based on the result, the assumption was made that it would have a significantly greater effect on a railway system with more traffic - for example Stockholm - than for the simulated system in this study.  The conclusion of the study is that different driver behaviours have an effect on headway and punctuality analyses. However, it is not possible to obtain an exact value on how punctuality and runtimes are affected by variations in train driver behavior with the simulation methods used currently in Sweden.