Complex sentence: It has two decks, one for road (two lanes) and one for railway traffic, as well as sidewalks for pedestrians, and was constructed in two and a half years with the aid of the Soviet Union.
Split into simpler sentences: It has two decks, one for road (two lanes) and one for railway traffic, as well as sidewalks for pedestrians. The bridge was constructed in two and a half years with the aid of the Soviet Union.