FE-modeling is a rapidly spreading method to analyze structures nowadays. With this theunderstanding of the outcome is of very high importance and potential inaccuracies areimportant to find so that faulty and over dimensioning of the structure does not occur whichleads to unnecessary costs. One of these inaccuracies is the unrealistic sectional forces that occurdue to thermal effects in the transversal direction for concrete frame bridges which leads to anexcessive amount much reinforcement in the structure than actually needed. This has beenstudied with several cases by using two approaches on how to apply the temperature in the framebridge, only in the superstructure and in the whole structure, but also by analyzing severalboundary conditions. By examining the results for the sectional forces and stresses one of thetemperature approaches could be disregarded because of the extreme values in the transitionbetween superstructure and support. But the other approach was much more useful because ofits better compliance with reality. With these results and by calculating the reinforcement neededfor the worst case, one model has been found to be the most favorable and can be used whenmodeling concrete frame bridges with acceptable outcome. The study resulted in a model whereone applies a varying temperature on the whole structure, with spring boundary conditions over asurface that represents the bottom slab.