Motorists traveling along Lahainaluna Road will cross the new Lahaina Bypass via a slender 130-foot single span, cast-in-place post-tensioned concrete, rigid frame bridge with integral abutments. 

The superstructure consists of multiple T-shaped girders of varying width and depth.  The girder depths vary from 3’-8” at midspan to 5’-8” at the abutments located at each end of the bridge span.  After the superstructure was stressed and locked with the abutments, the T-shaped girders and abutments function together as a rigid frame.  An advantage of the frame’s rigidity is that the T-shaped girders resist the applied loading with a combined mechanism of “beam flexure” and “arching” to help reduce the long term deflection and to minimize abutment footing requirements. 

The shallow girder depth at mid-span is facilitated by taking advantage of the massive basalt rock formations at each abutment to resist the thrust from the rigid bridge frame.  The natural aesthetic of efficiency of purpose in the structural system is achieved by using the structural restraint provided by the basalt combined with the strength of the post-tensioned reinforced girders. The naturally pleasing shape of the parabolic girder soffit also provides for a clean and clear bridge elevation