The Tampa Bay area is home to over 4,000,000. Clearwater anchors northern Pinellas County while St. Petersburg with its Downtown along Tampa Bay, spreads across the southern peninsula. Tampa, home to both MacDill Air Force Base and Port Tampa Bay, encircles Hillsborough Bay to the east, with unincorporated suburbs expanding outward to encompass Brandon, Riverview and Ruskin.
The original layout for the Tampa Bay Interstate network took Interstate 4 west from Tampa to St. Petersburg and Interstate 75 south from Pasco County to an end at the Downtown Interchange near Ybor City. Changes were made in 1971, when I-75 was routed southward over I-4 west from Downtown Tampa to Pinellas as part of its extended alignment south to Naples. The eastern alignment of I-75 around Tampa Bay was given the designation of Interstate 75E. This change lasted just two years, when I-75 shifted eastward over proposed I-75E and I-275 was designated over the loop through both Tampa and St. Pete.
Interstate 275 crosses the cable stayed Sunshine Skyway Bridge over the mouth of Tampa Bay. On May 9, 1980, the southbound span of the original Sunshine Skyway Bridge (a steel truss bridge) collapsed when the Summit Venture freighter collided with a bridge support. This led to two-way traffic on the remaining northbound span until the replacement was built. Ultimately, the old bridge was removed, though portions of the approach in both directions were retained for use as fishing piers run by the state park system.
The following are key dates in the history of Interstate 275 in Florida:1
- 1973 – Interstate 275 created when Interstate 75 is shifted from the St. Petersburg-Tampa route to the Tampa Bay bypass. At that time, Interstate 275 was complete from 38th Street North in St. Petersburg north to Lutz. The Sunshine Skyway also carried Interstate 275 shields. The portion of Interstate 275 between the skyway (near Maximo Point) and 38th Street North was unconstructed.
- 1975 – Interstate 275 under construction from 5th Avenue South north to 38th Street North.
- 1977 – Interstate 275 opened from 5th Avenue South north to 38th Street North in St. Petersburg.
- 1980 – Interstate 275 under construction from Interstate 75 near Gillette west to Terra Ceia. Tragedy struck I-275 when the ship Summit Venture collided with the original Sunshine Skyway. 35 people died in this accident, and one of the two spans collapsed.
- 1981 – Interstate 275 under construction from Maximo Point (northern end of the Sunshine Skyway) north to 5th Avenue. The northern terminus of Interstate 275 was extended up former Interstate 75 to near Worthington Gardens.
- 1983 – Two sections of Interstate 275 opened: the south interchange with I-75 and the section of I-275 from Maximo Point (northern end of the Sunshine Skyway) north to 5th Avenue South.
- 1984 – Replacement Sunshine Skyway (a new cable-stayed bridge) was under construction.
- 1987 – New Sunshine Skyway opened on April 30th. At that point, Interstate 275 was complete.
The Sunshine Skyway opened to traffic following a ribbon cutting ceremony on April 30, 1987.3 Festivities were held for the $240 million span on February 7, 1987. Events included a public bridge walk a parade along the north causeway and a dedication ceremony held at Blackthorn Park.4 Construction of the 76 foot diameter concrete pillars supporting the concrete segmental bridge got underway September 24, 1982. The pillars were placed at 1,200 foot intervals, 400 feet farther apart than the old Skyway Bridge.5 The 24 piers holding the northern half of the cable-stayed span were in place by February 1985 as work progressed on the 40 foot wide roadway decks. Construction on the piers for the Skyway’s southern half continued along with the pylons for the two 425 foot high towers.5,6 The 1,200 foot long main span provided 175 feet of navigational clearance.6
Work on the Skyway fell behind schedule due to cracks forming in the concrete segments. Although $16 million over budget, it was previously scheduled to open in August 1986.7 Further delays plagued the project when a gantry used to lift a 220 ton section of concrete roadway collapsed on July 30, 1984. Bridge contractors also took longer to cast the roadway segments than previously anticipated, pushing back completion to Fall 1986.8
When the 22,000 foot long Sunshine Skyway opened to traffic, portions of the former bridge were repurposed into fishing piers. 3,360 feet of the Pinellas County pier were retained while the Manatee County pier represented one of the longest piers in the world at 8,400 feet in length. The steel superstructure of the old bridge was dismantled and sold as scrap. Some of the rubble from the concrete support columns from the old span was used to create artificial reefs nearby.6