This paper reports on the transition from design to laboratory validation and construction of an off-system concrete bridge deck with open-post railings that use prefabricated glass FRP (GFRP) reinforcement. The deck reinforcement consists of modular stay-in-place (SIP) panels made of two-layer gratings that are fabricated in a quality-controlled environment with off-the-shelf pultruded shapes, and an epoxy bonded formwork plate. Constructability is improved by eliminating tying of reinforcing bars in place, while the light weight of the GFRP grating facilitates handling and installation. In addition, the use of a SIP system, not always practical with metallic forms, eliminates the need for extensive formwork. Pre-assembled cages made of pultruded GFRP deformed bars are used as reinforcement for the open-post concrete railing and its connections to the deck, thus eliminating time-consuming assembling on site. The reinforcement strategies enabled to construct the cast-inplace deck and railing in five days, with a 70% time saving and easier field work compared to similar bridges where conventional steel reinforcement is used.