The main aim of the diploma thesis is a design of two bridges on D1 highway (Říkovice – Přerov). Structural system of these two bridges is a seven spans continuous beam. The bridges span the rail track and road I/35. The structural system of these two bridges is identical. The preliminary design is processed in two options. The first one considers the use of post-tensioned pre-casted beams PETRA with cast-in place cross beams and composite bridge deck. The second draft considers the use of two slab-beam with the cross beams. Effects of loads were calculated in SCIA Engineer program. The build-up phases were assessed by TDA method. The assessment of the structure was made according to EC.