The bi-directional plate bending behavior of a pultruded GFRP bridge deck system with orthotropic material and system properties was investigated by means of two full- scale experiments and numerical modeling. Furthermore, the maximum span of the deck between two main girders was determined using Eurocode loading and presupposing a maximum deflection ratio of span/300. Compared to an isotropic plate-strip, the bi-directional behavior of the orthotropic deck was not very pronounced. Nevertheless, selecting experiment specimen with five profiles instead of only three reduced the maximum deflections at the serviceability limit state (SLS) by ca. 50%. Therefore, since the SLS governs in the design of GFRP bridge decks, the possible contribution of bi-directional plate bending is not insignificant and should be considered and improved in order to fully exploit the potential of pultruded GFRP bridge decks.