Straight girders with curved deck - Line girder analysis

[PAK_ENG]

Hi there. I am working on a bridge widening project. Structure is three simple spans, curved alignment with baseline radius of 1900', but the existing eight girders are straight steel girders with varying skew (approximately 45 degrees) with varying deck overhang. The two new girders will also be straight steel girders. Can I use a line girder analysis program such as Merlin Dash for the design and analysis in this situation? We have DESCUS, but looking at that program, it looks like a time consuming process to input the geometry for all 10 girders. How close of an approximation would Merlin Dash give me versus Descus? Is there a certain radius and skew in which line girder analysis is not appropriate?

Thanks for the help!