As explained in the FreightWaves Classics article about Interstate 2 (I-2), there are 70 primary interstate highways in the Dwight D. Eisenhower National System of Interstate and Defense Highways (commonly known as the Interstate Highway System, or IHS). The IHS is a network of the major freeways in the United States. The oldest parts of the interstate system date back to the 1950s, although planning for the system began prior to World War II. To learn more about their history, read previous FreightWaves Classics articles here, here and here.

In this article and future articles, information about specific interstates will be explored. As most people know, interstate highways are assigned one- or two-digit route numbers (such as I-10 or I-55). Associated “auxiliary” interstate highways (spurs and loops) receive three-digit route numbers (such as I-270, I-495, etc.). 

Generally, odd-numbered interstates run south-north, with lower numbers in the West and higher numbers in the East. Even-numbered interstates run west-east, with lower numbers in the South and higher numbers in the North. (This is the opposite of the national highway system, whose lowest numbered north-south routes are in the East, the highest numbered routes in the West. 

Interstate highways whose route numbers are divisible by 5 usually represent major coast-to-coast or border-to-border routes (for example, I-10 runs from Santa Monica, California, to Jacksonville, Florida, from the Pacific to Atlantic oceans). 

This map shows the route of I-4 from Tampa (western Florida) to Daytona Beach (Florida’s East Coast). (Map:


Interstate 4 (I-4) is another intrastate interstate – built to interstate standards but located wholly within Florida. I-4 was one of the first interstate highways constructed in Florida. The highway runs on a southwest to northeast route across the Florida peninsula. Along its course it connects several of Florida’s key metropolitan areas, including Tampa-St. Petersburg, Lakeland-Winter Haven, Orlando and Daytona Beach. Known as the I-4 corridor, this area has registered some of the fast growth in Florida over the past 50 years. 

The Florida Department of Transportation (FDOT) maintains I-4. The highway is 132.3 miles long and runs generally southwest–northeast. I-4 begins at an interchange with I-275 in Tampa and ends at an interchange with I-95 in Daytona Beach. The interchange with I-275 is near downtown Tampa and is known by locals as “Malfunction Junction.”

A marker for Interstate 4. (Photo:

Construction on I-4 began in 1958 and its first segment (from Plant City to Lakeland) opened in 1959. The entire (original) highway was completed in 1965. However, like most interstate highways, construction to improve the highway has been going on almost continuously since. I-4 maintains a diagonal, northeast–southwest route for much of its length, although it has an even number (usually used for east-west interstates). The highway roughly follows the path of an intrastate railroad built in 1884. 

The original plans called for I-4 to extend to St. Petersburg, with the western end of the highway set at Central Avenue (County Road 150) in St. Petersburg. However, the western end was stopped at Malfunction Junction in 1971 when I-75 was extended. Later, that section of roadway was redesignated to be part of I-275.

An aerial view of I-4 in Orlando. (Photo: Florida Department of Transportation)

Population increases lead to new construction

When the first segment of I-4 opened in 1959, the population of Florida was about 5 million people. By 1970 the population had increased to 6.8 million and by 1980 the population was over 10.2 million. Now there are more than 21 million residents of Florida and it is the third most populous state in the United States. 

With the ever-expanding population and development in Florida, I-4 has become a major transportation corridor. Originally a four-lane highway, it quickly became inadequate to meet the needs of the growing population. A number of expansion programs were completed between the mid-1990s and 2008; they increased I-4’s capacity between Tampa and Orlando. In addition, a six-lane expansion through Volusia County was finished in 2017.

Other proposals to add lanes and to make other improvements to I-4 were promoted; most were controversial. For example, in October 2003, the “Mobility 20/20” tax plan proposed an expanded Interstate 4 through the Orlando metropolitan area, but it was defeated by voters, in part because of opposition to toll lanes on I-4. 

The logo for the “I-4 Ultimate Project”

I-4 “Ultimate Project”

The I-4 “Ultimate Project” is a $2.3 billion project that upgrades 21 miles of Interstate 4, from south of SR 435 in Orange County to north of SR 434 in Seminole County. The mega-project began in early 2015 and is scheduled to end by 2022. The focus of the work is the rebuilding of 15 interchanges, the replacement of 75 bridges and the addition of four Express Lanes along I-4’s median.

Adjacent toll roads

The traffic on I-4 grew as the state’s population grew. A number of toll roads were built to provide alternatives to I-4 and to serve as commuter routes across central Florida. These routes have relieved some of the congestion on I-4, but the burgeoning population has outstripped the capacity of most of the roads. 

While all of Florida has grown in population, the growth in the area around Orlando has been some of the most dramatic. With population increases came traffic problems. One of the worst bottlenecks in the state was the original I-4 interchange with the East-West Expressway. The term “highway hostages” was coined in the 1980s to describe people stuck in long commutes to and from Orlando on I-4.

A map of the now-cancelled Florida High Speed rail line.
(Image: Federal Railroad Administration)

High-speed rail line

At one time, the median of I-4 between Tampa and Orlando was planned to be the route of the Florida High Speed Rail line between those cities. Florida voters passed a state constitutional amendment in 2000 to build high-speed rail between the state’s five largest cities. The project was cancelled in 2004, but was revived in 2009. The federal government awarded Florida over $2 billion (nearly the entire projected construction cost) to build the line in 2010. Work was to begin in 2011 and was scheduled to be completed by 2014. However, Governor Rick Scott (now a U.S. Senator) rejected the funding, which halted the project before it began.

Future construction

Many of the interchanges along I-4 that were built after 1970 were designed to accommodate later projects to widen the highway. Therefore, I-4 could be widened up to 10 lanes without having to extensively modify the interchanges. Among those interchanges are the I-75 stack (built in the 1980s) and several interchanges that were built in the late 1980s and early 1990s that serve the Walt Disney World Resort area. 

Like most interstate highways, Interstate 4 has been widened and upgraded, as well as been redesigned in places to improve safety. And despite these improvements, like most interstate highways it is constantly behind the “population curve,” meaning it cannot handle the traffic volume generated by the population. Construction of the Interstate Highway System began at a time that the U.S. population was less than 169 million; today the nation’s population is 332 million. And Florida has grown more than many other states. It was the 32nd-most populous state in 1900; by 1960 it was the 10th-most populous and now it is the third-most populous. 

NOTE: The author thanks the websites of the Federal Highway Administration and for information that contributed significantly to this article. Both websites have a great deal of information about the Interstate Highway System, its individual highways and the history of the system.