I-275 (SR 93) Overpass Bridges

The I-275 (SR 93) corridor is a heavily travelled limited access facility used by commuters to travel to and from downtown Tampa in Hillsborough County, Florida. The goal of the project was to provide increased shoulder widths to improve the safety of the roadway.

DRMP led the widening design of three overpass bridges along I-275, Bird Street, Waters Avenue and Yukon Street. All three bridges were super-elevated in a curved alignment. The existing structures consisted of AASHTO girders and were widened using Florida-I Beams. A challenge on this project included connecting the super-elevated northbound and southbound bridges in the median to create one continuous deck. This resulted in a thickened deck and modified median barrier height. The foundations included drilled shafts at Bird Street and Waters Avenue for the end bents and pier. At Yukon Street, a relic sinkhole was identified early in the project and 18-inch open-ended steel pipe piles were used to minimize pile lengths and for easier splicing during piling driving due to variable soil conditions. All construction activities were completed within a confined median zone. 

The expanded limited access highway benefits the community by increasing inside shoulder widths which is a safety benefit to motorists.  The previous roadway had minimal inside shoulder widths which offered no refuge to motorists during traffic incidents or breakdowns.  The widened structures will provide a smooth traffic flow that will meet the growing capacity demands of the highway while maintaining the highest safety standards.