I-275 at I-4 Downtown Tampa Interchange (DTI) Design-Build, FDOT District 7

Our approach allowed for off-line construction of the new ramp and flyover bridge, which minimized disruption to existing Ramp NE traffic during construction. With the new flyover constructed, traffic uses this ramp while improvements to the existing ramp are completed, reducing the number of traffic shifts compared to the widening concept and providing three total lanes for these movements, compared to two lanes in the original concept.

Additionally, construction of a new ramp and flyover eliminated over 100 detours, totaling six months of nightly/weekend closures. Other significant ATCs included introducing tie-down slopes on Ramp NE to eliminate the need for an MSE wall and a temporary critical sheet pile wall; modifying the profile of Ramp B to eliminate the potential for drainage challenges and future deck cracking; replacing roadway construction at the North 10th Street and East 14th Street intersection with a two-way, stop-controlled intersection to eliminate drainage reconstruction and reduce road closures; and, using an alternate 60-inch drain pipe to reduce 100 feet of pipe length and keep operations within FDOT right-of-way. In addition, we lowered Ramp NE profile to enable a smoother transition of traffic shifts by expanding a pinch point, which also helped design a critical existing wall strengthening section. Our innovative designs ensure the timely completion of the project while reducing long-term maintenance, simplifying temporary traffic control plans, reducing overall system traffic delay, and minimizing construction complexities.