We investigate the characteristics of crossing and branching nodes in monolayer soft-lithography-based polymer optical interconnects with experimental and theoretical analysis. The theoretical crosstalk, as calculated by a function of crossing angle, was determined for a set of interconnect pairs with varying cross-sections, and was compared with experimental measurements. Furthermore, a suitable branching angle was found for branching node and the effects of short-distance mode scrambling in highly multimode polymer waveguides were studied in detail. It was found that mode-filling occurred within a propagation distance of 1.5mm for a 50×50μm2 cross-section for VCSEL coupling; however, complete scrambling of ray direction required a propagation distance of more than 5 mm.