Brazoria County, Texas
BBI was awarded Segment 1 of a one-mile long managed lanes improvement project for the Brazoria County Toll Road Authority in 2014. This project, the Brazoria County contribution to a major investment project, included roadway, drainage, and two bridges. The design utilized the median area, which contained a conveyance ditch for the SH 288 mainlanes, to a bi-directional concrete tollway, with median barrier and shoulder, and a 10-foot outside shoulder and barrier rail. Bridges were designed over the American Canal and the Mustang Bayou.
BBI engineers coordinated closely with the adjacent segment engineers, to assure continuity of design across segment lines. Cross drainage was computed to include flows contributed from Segment 2 from the north, with outfalls and detention designed accordingly. In order to contain the 100-year flow coming off the tolled lanes, BBI engineers proposed a raised slotted rail system along with storm drain trunk lines on both the southbound and northbound outermost lanes that would capture the 100-year runoff from the tolled lanes, while allowing higher flows to cross over the existing mainlanes. This design, accepted by the client for use in other segments, assured that the existing lanes would not be inundated with excessive runoff from more frequent rainfall events.
The project was executed in four milestone submittals (30-60-90-100%) which required bid-ready plans, specifications and estimates. BBI held precisely to the client-driven schedule, and delivered an on-time and within-budget design.