Modular expansion joint is a mechanical device installed in bridge expansion joint openings. The primary function of the Modular expansion joint is to permit vehicle traffic to travel smoothly across large expansion joint openings. It does this by dividing the large expansion joint openings into a series of smaller openings called cells. These cells work in series to accommodate the necessary thermal bridge movement (expansion and contraction) while providing a smooth riding surface for bridge vehicle traffic. Modular expansion joint is normally used for expansion joints with a movement range exceeding 75 mm. Modular expansion joint also has the secondary function of protecting the surrounding bridge superstructure and substructure. All modular expansion joint cells are equipped with watertight sealing elements that prevent debris, water, and corrosives such as de-icing chemicals from passing through bridge expansion openings and damaging superstructure and substructure components.