1959 is the moment I-4 appeared on the maps. These earlier spans were probably planned as an US 92 bypass road around Lakeland and Plant City, based on the strange alignment of Lakeland's Memorial Boulevard (US 92 & "To US 92") and property lines on the west position of Plant City (See Hillsborough County Property Appraiser maps). The very first span was from Lakeland to Plant City, with construction beginning from Tampa to Plant City and the Howard Frankland Bridge. I-4 was inaugurated in 1960 together with the Howard Frankland Bridge, from East Tampa to Lakeland as well as from Lake Monroe to in the proximity flake Helen. Proposed sections that year included those in St. Petersburg, in Tampa, from Lakeland to Orlando, and from Lake Helen to Tiger Bay State Forest. By the year 1961, the section Lakeland - Orlando had been constructed. The span of the I-4 Lake Helen - Daytona Beach underwent several construction operations. Proposed routings include sections in Tampa, in St. Petersburg, as well as from Sanford to Orlando. By 1963, merely the span in Tampa still not built was between Sanford and Armenia. In Orlando, I-4 was fully constructed up to Robinson St, and was named "Orlando Expy. In 1964, the south-western terminus of I-4 was cautiously established at South Pasadena on the Gulf of Mexico after having followed an older rail road corridor. This routing was also rejected. In 1967, the interchange with I-75 (in present days called I-275) was constructed, nowadays called Malfunction Junction. In 1969, I-75 was extended westwards along I-4 to St. Petersburg. In 1971, the entry of I-4 was shortened to Malfunction Junction in Tampa. Apart from the rebuilding / widening plan in the later 1990's, I-4 has not changed ever since. There are some good shots of the earlier I-4 in the Florida State Photographic Archives - type in "Interstate 4”.
In present days Interstate 4 is actually shorter that it had been previously conceived. As originally envisioned, I-4 was linked southwest with Interstate 275 from its western terminus into St. Petersburg; back then Interstate 75 was the very name of the Interstate 275 north of Interstate 4. In those days Interstate 75’s end was at its junction with Interstate 4 in the momentous downtown Tampa. For some time there were no plans in sight for any further south extension of the Interstate 75.
The momentous Downtown St. Petersburg was the very end of the Interstate 4 in all this time. Interstate 4 was even planned to be extended further west up to the splendid Gulf of Mexico. In the end this plan was given up too. This way the Interstate 4 travelled all the way to the historic downtown St Petersburg. Nevertheless the extension of Interstate 75 south to Fort Myers and Naples resulted in shortening the Interstate 4 up to downtown Tampa. These changes occurred mostly between 1970 and 1972. The remarkable Howard Frankland Bridge co-signed as Interstate 4 and Interstate 75A 1971 has been shown this way by a Esso Map of Florida; in 1973 Interstate 275 was the very name of this bridge, because the Interstate 75 hadn’t been yet constructed to the east of Tampa. The whole former Interstate 4 west of its existing intersection with Interstate 275 can now be considered as being part of the Interstate 275.
Here are some important dates in the very history of I-4:

• 1959 – I-4 was opened from Plant City to Lakeland (this was the very first segment to be opened). Interstate 4 under construction (1) from Plant City to Tampa and (2) on the Howard Frankland Bridge (which was then part of Interstate 4)
• 1960 - Interstate 4 was opened (1) the Howard Frankland Bridge, (2) actually from East Tampa east to Lakeland, and (3) moreover from Lake Monroe to in the proximity ofLake Helen. The sections in St. Petersburg, in Tampa, from Lakeland to Orlando, and from Lake Helen to Tiger Bay State Forest were proposed but have still not been constructed.
• 1961 - Interstate 4 was opened from Lakeland to Orlando and was under construction from Lake Helen east to Daytona Beach. Segments like St. Petersburg, in Tampa, and from Orlando to Sanford were proposed ones but though unconstructed.
• 1963 – A section of the I-4 between Armenia and 22nd Street had also to be constructed in Tampa.
• 1963 - In Orlando the Interstate 4 met up with the Robinson Street and was named "Orlando Expressway."
• 1969 - Interstate 75 which was extended south had the same alignment as Interstate 4 from Tampa southwest to St. Petersburg.
• 1971 – I-4 was shortened to the transition with I 75 (now labelled as Interstate 275) in Tampa. I-4 is now fully constructed from Interstate 275 in Tampa and up to I 95 in the spectacular Daytona Beach.

From Wikipedia, the free encyclopedia

• Interstate 4 can be regarded as one of the fists interstate segments in Florida to be constructed. Moreover this is the very first segment opened between Lakeland in and Plant City in 1959.
• In 1960/1961, not only the Howard Frankland Bridge, but also the segment from 50th St in Tampa to Plant City, as well as the segment from Lake Monroe to Lake Helen were open to traffic.
• 1962 was the completion year of the segment from Orlando to Lakeland.
• Various segments had already been constructed by the very mid 1960s. We can mention here the Malfunction Junction in Tampa as well as some parts of I-4 through Orlando.
• In the late 1960s South Pasadena had been envisaged as the initial western terminus. However this plan had been rejected because of the local disagreement. In this way I-4 only went southwest until the 9th St N in the amazing city of St. Petersburg.
• The whole interstate has been built by the late 1960s. Nevertheless the western terminus was truncated to Malfunction Junction in 1971 when Interstate 75 travelled up to the significant Frankland Bridge. In the end that span was again renamed and became part of I-275.
• The interchange with today known as Interstate 75, was constructed in the early 1980s.
• Various interchanges in the neighbouring area of Kissimmee were built/upgraded in order to be able to cope with the increasing traffic to and from the exhilarating Walt Disney World. This actually happened in the early/mid 1990s. Nevertheless I-4's main lanes didn’t undergo widening works in this very process. The Southern Connector had been also extended to I-4.
• In 2004 and 2005 the I-4/I-275 interchange (Malfunction Junction) was reconstructed, and I-4 currently undergoes dramatic renovations in order to be expanded from 4 to a total amount of 6 lanes (even 8 lanes in particular road sections). The work is partially completed.
• I-4 is to be widened again to amount at least 10 lanes (5 in each direction). There had been conducted all sorts of studies for this very project and the construction should begin sometime in the 2010s. 2020 is the completion year of this project.
• The combination of the Tampa, Lakeland, Orlando and Daytona Beach metropolitan areas is regarded as the I-4 Corridor, since all four are linked by the here above interstate.
• During the 2004 President Election campaign, the I-4 corridor was considered to be a very important location for the political activity in the state of Florida. The communities along the I-4 corridor were thought to have higher proportions of undecided electorate in comparison with the more Republican- or Democratic-leaning areas in Florida.
• The devastating hurricane Charley can be once in a while regarded as the "I-4 Hurricane” because of the fact that this hurricane often follows the Interstate 4 over its last 100 miles (160 km) causing severe damage in Central Florida.

Furthermore the I-4 can also be referred to as one of the routes on the Interstate System that doesn't display a child 3-digit route.