From Miami north to Tampa, Interstate 75 parallels U.S. 41. U.S. 41 is a toll-free alternative to I-75 across the Everglades and through Big Cypress National Preserve, but with only two lanes and limited passing opportunities. Advancing west to the turnoff for Marco Island at SR 951, U.S. 41 becomes a heavily developed arterial with four to six lanes. With the completion of Interstate 75 through Southwest Florida in the mid-1980s, through traffic diverted from U.S. 41 to I-75. The rural corridor along I-75 eventually succumbed to the construction of housing, retail, business parks and entire communities such as Lakewood Ranch. Previously empty interchanges grew to include traveler services, apartment complexes and condominiums.
Traffic congestion increased between Naples and Tampa due to the explosive growth of this region, and by 2019 the last four lane section (in Charlotte County) was widened. A previous widening plan under consideration for Interstate 75 in Collier and Lee Counties north of SR 951 focused on financing expansion with toll (HOT) lanes. In 2005, state legislation approved the Southwest Florida Expressway Authority (now defunct) to oversee this future widening. Commonly known as the IROX project, the first 30 mile portion transformed Interstate 75 from four to six lanes between Collier County Road 846 (Immokalee Road) near North Naples to SR 884 (Colonial Boulevard) in Ft. Myers.
Until 1968, when the extension of I-75 south from Tampa to Naples was approved by the Federal Highway Administration (FHWA), Interstate 75 concluded at the Downtown Interchange where I-4 and I-275 meet in Tampa. I-4 continued southwest along what is now I-275 to St. Petersburg. So when it came time to extend Interstate 75, planners had a decision: should I-75 continue through Tampa and St. Petersburg or should it be realigned inland as a bypass of the metropolitan area? The initial decision was to route I-75 along the current alignment of I-275 through both Tampa and St. Petersburg, while Interstate 75E was proposed to bypass the urban area to the east. By 1973, the current configuration for I-75 was selected, and the freeway was completed east of Tampa Bay in 1986. Even so, the unmarked Florida state road designations allude to the former route of I-75, with SR 93 accompanying I-275 through St. Petersburg and Tampa and SR 93A overlaying I-75 around the east side of Tampa Bay.
Interstate 75 widens to eight lanes through the Brandon area east of Tampa due to commuter traffic. North of Tampa, I-75 becomes the main gateway corridor from the Midwest states to Florida. Traffic is funneled to I-75 via I-74 and I-64 from Indianapolis, Milwaukee, Chicago, St. Louis, and Minneapolis. The I-75 mainline carries travelers from Detroit and Ontario. Many segments of I-75 are subject to delay as a result of the increased traffic related to the Christmas holidays and spring break.
The following are key dates in the history of Interstate 75 in Florida:8
- 1960 – The proposed segment of I-75 from Alachua north to the Georgia State Line was shown for the first time on maps
- 1962 – I-75 opened from Lake City to Genoa (first segment to open). I-75 under construction from Ellisville to Lake City and from Genoa to the Florida-Georgia State Line.
- 1963 – I-75 under construction from Wildwood north to Lake City.
- 1965 – I-75 under construction from I-4 in Tampa north to Chapman and from Wesley Chapel north to Wildwood.
- 1967 – I-4 and I-75 interchange in Downtown Tampa was constructed. Joining I-4/275 today, this exchange is commonly known as Malfunction Junction.
- 1967 – In-75 opened from Wesley Chapel to Wildwood.
- 1968 – All of Interstate 75 north of Tampa was opened except for the short segment in Tampa between the Hillsborough River and Fowler Avenue.
- 1969 – I-75 was extended southwest along I-4 into St. Petersburg. I-75 had a new proposed routing up from Bonita Springs (north of Naples) to Rubonia. The Sunshine Skyway was also added to I-75.
- 1971 – Initial proposal to extend I-75 south from Naples to Miami considered along U.S. 41 (Tamiami Trail) corridor and SR 836 (Dolphin East-West Expressway) in Miami. This proposed route was shifted to the Alligator Alley alignment in 1977. As a result of the truncation of I-4, I-75 was extended southwest through Tampa to St. Petersburg.
- 1972 – The southern terminus of I-75 was at the junction with SR 689 (54th Avenue N and Haines Road) in St. Petersburg.
- 1973 – I-75 in St. Petersburg opened from 38th Avenue N to 54th Avenue N. Shortly thereafter, the I-75 designation was shifted to the bypass route, while I-275 replaced I-75 on the city route.
- 1977 – Proposed route of I-75 from Naples to Miami shifted to the two-lane Alligator Alley (Everglades Parkway). Signs for I-75 were placed on the Alligator Alley. Another new proposed route for I-75 linked Golden Gate to Bonita Springs.
- 1978 – I-75 under construction from Estero to Tropical Gulf Acres.
- 1979 – I-75 opened from Estero to Bayshore and under construction from (1) near Opa-locka to near Andytown (U.S. 27), (2) SR 951/Golden Gate north to Estero, and (3) from Tropical Gulf Acres to U.S. 301 near Ellenton.
- 1980 – I-75 opened (1) from Bayshore to Harbour Heights and (2) North Port to Ellenton. Interstate 75 under construction from Ellenton to SR 672.
- 1981 – I-75 opened from County Road 846 north to U.S. 301. I-75 is under construction from U.S. 301 north to I-275 at Lutz.
- 1982 – I-75 opened from Ellenton to CR 672.
- 1983 – I-75 opened from CR 672 to U.S. 301 near Temple Terrace.
- 1984 – I-75 opened (1) from SR 820 to County Road 818 and (2) from Bruce B. Downs Boulevard north to Interstate 275 near Lutz.
- 1985 – I-75 opened from CR 672 north to Bruce B. Downs Boulevard, thus linking the northern and southern sections of I-75 and completing the Tampa Bay Bypass.
- 1986 – I-75 opened from SR 826 (Palmetto Expressway) in Hialeah north to U.S. 27 at Andytown. A connection to Interstate 595 began construction. The only remaining unfinished part of I-75 was the Alligator Alley corridor.
- 1989 – Construction begins to upgrade the Alligator Alley from a two lane highway to a four lane freeway.
- 1990 – The improved I-75 (Alligator Alley) opened from Andytown west to Big Cypress.
- 1992 – I-75 (Alligator Alley) opened from Big Cypress west to SR 29.
- 1993 – I-75 (Alligator Alley) opened from SR 29 to SR 951 near Golden Gate. I-75 is now complete from SR 826 (Palmetto Expressway) in Hialeah north to the Georgia-Florida State Line, which includes both its original, planned route and the 1971 southerly extension to the Miami metropolitan area.
Within southern Georgia, Interstate 75 had several business loops that served cities such as Valdosta, Tifton and Cordele. These business connections lead to U.S. 41 through these towns. Interstate 75 meets I-16 at Macon, which connects Savannah to Atlanta. With six overall lanes, Interstate 475 is the preferred bypass route for through traffic between Florida and Atlanta, and the freeway also hosts the last northbound rest area until beyond Atlanta.
All of Interstate 75 between the Florida state line and Macon carries six overall lanes. The stretch between Exit 18 (SR 133) and the Crisp/Dooly County Line near Milepost 106 was expanded as part of a $776 million project constructed between 1996 and April 8, 2011.2 Work added lanes on the inside of the freeway right of way with a concrete barrier median separating traffic. Many overpasses were also raised to current Interstate standards.
Within the city of Macon, long term construction upgrades I-75 from Hardeman Avenue to Pierce Avenue. Work rebuilds the exchange with I-16 (Exit 165) to eliminate left exit ramps and weaving traffic. Planning to improve the deficiencies at this interchange have been underway since the early 1980s. These resulted into an agreement on the preferred alternative at a Public Information Meeting held on October 24, 2000. 3.3 miles of the freeway was expanded leading northwest from Macon by November 2013,3 but continued delays pushed back road work at I-16 to Fall 2016. Split into six phases, the last section of the I-16/I-75 Interchange Project is anticipated to go to bid in 2023. Work on the overall project continues to 2030.
Continuing northward to the Atlanta metropolitan area, Interstate 75 maintains six lanes to McDonough, where the tolled Express lanes commence. The managed lanes run between the north and southbound roadways between SR 155 (Exit 216) and the split with I-675 (Exit 227) at Stockbridge. Within the Perimeter Highway (Interstate 285), I-75 combines with I-85 along the Downtown Connector.
Interstate 75 through Atlanta - 1962 Georgia Official Highway Map
Traffic and capacity issues plague the Atlanta metropolitan area routine and improvement projects are always ongoing or in development. One such plan was the “Freeing the Freeways” mega project. Split in a series of projects strung out between 1976 and 1994, work along I-75 rebuilt the freeway from the Downtown Connector northwest to the I-285 from 1982 to 1987. Redesign of the Downtown Connector, including an overhaul of the Capitol Hill Interchange with Interstate 20, followed between 1985 and 1988. I-75/85 was expanded to as many as 16 lanes.
The arrival of the Summer Olympic Games in 1996 in Atlanta was preceded by the restriping of Interstate 75 to accommodate HOV (High Occupancy Vehicle) lanes between May 1995 and May 1996. The left lanes of I-75 and other Atlanta area freeways were restricted to HOV-2 eligible motorists. Lanes were enforced 24 hours a day.
Some HOV lanes in the Atlanta were converted to tolled express lanes. With the success of the I-85 Express Lanes from Atlanta northeast to I-985, efforts to expand I-75 with the managed lanes followed. Construction underway between October 2014 and December 2016 added two reversible HO/T (High Occupany/Toll) lanes along Interstate 75 from SR 155 (McDonough Road) north to SR 138 (Stockbridge Highway). The Northwest Corridor project added Express Lanes from I-285 to Hickory Grove Road and along I-575 north to Sixes Road. The 29.7 mile long system was constructed from October 2014 to September 8, 2018 at a cost of $834 million.9
Leaving Atlanta, Interstate 75 leads northwest toward Chattanooga, Tennessee with no less than six lanes. The last section of I-75 completed between Tampa, Florida, and Sault Ste. Marie, Michigan, was a section four miles north of Marietta, Georgia. It opened on December 21, 1977.10
Once at Chattanooga, Interstate 75 changes direction from northwest to northeast. U.S. 41 departs toward Nashville and Chicago, while I-75 picks up U.S. 11. Here, I-75 provides the connection between I-59 and I-81, both of which parallel the U.S. 11 corridor. Interstate 75 combines with I-40 east from near Eaton Crossroad into the city of Knoxville with as many as eight overall lanes.
Within Knoxville, I-75 originally looped east to Downtown along an extended overlap with I-40 to Interstate 275 north. The American Association of State Highway and Transportation Officials (AASHTO) approved relocating I-75 onto the western leg of Interstate 640 (which was scheduled to open in December 1980) on June 25, 1980. The Tennessee Department of Transportation (TDOT) application to AASHTO cited the following reasons for the numbering changes:
1. By routing I-75 along the western leg of I-640 rather than its existing route through town, travel distance can be reduced by 1.79 miles, a substantial savings in travel time and fuel consumption.
2. At the present time through traffic on I-75 must traverse nine interchanges and one major directional interchange along its route through town. The proposed routing along I-640 includes only two interchanges. With less merging and diverging traffic conditions, the routing along I-640 would be desirable from a safety standpoint.
3. With this change, elimination of overlapping major Interstate routes, (I-40, I-75) would result in the downtown Knoxville area.
TDOT initially requested I-640 be truncated to a west end at the exchange with I-75/275. FHWA however disagreed, indicating that I-640 should become a portion of I-75. Though FHWA also provided the suggestion of:
The State is free, however, to place I-640 trailblazer signs on that section as well as on I-40 west of the interchange with renumbered I-75. Interstate 640 would then be from I-75/I-275 to I-40 in northeast Knoxville.
Some of the most beautiful mountain scenery along Interstate 75 can be found north of Knoxville en route to Kentucky at Jellico. This stretch of freeway parallels U.S. 25W.
The “Interstate 175 Corridor” feasiblity study in 2002 focused on a corridor paralleling I-75 in Kentucky and Tennessee between Chattanooga and Lexington. Unfunded, the concept outlined potential corridors along U.S. 27 or U.S. 127. It never gained traction.
I-71/75 between Fort Wright and Covington opened to traffic in Fall 1962. Known as “Death Hill” locally, the three-mile section of freeway lowers from a 370 foot hill near the city of Park Hills to the Ohio River at the Brent Spence Bridge. Numerous fatalities were recorded on this stretch through 1968 due to substandard design including the steep grade and weaving traffic at the interchange with Jefferson Avenue coupled with a dangerous S-curve. Speed limits were lowered and median barriers were separating the roadways by 1977, but the accident rate remained high.11
A new design for the Death Hill section of I-71/75 was selected by state highway officials in Spring 1981. A $46.5 million contract was subsequently awarded to rebuild the freeway on December 28, 1989. The project raised the base of the hill by 20 feet to improve the grading, added a truck climbing lane to southbound, removed the interchange at Jefferson Avenue in Covington, and straightened out the S-curve built in 1962. Work encountered numerous delays due to environmental issues, a union worker strike and the replacement of bad concrete among other items. Crews finished the highway project on September 1, 1994, nearly two years after the original completion date and $4 million over budget.11
Brent Spence Bridge
The Brent Spence Bridge, opened in 1963, is a double deck bridge that crosses the Ohio River between Covington, Kentucky, and Cincinnati, Ohio. In early 2004, the Kentucky Transportation Cabinet introduced six alternatives for the Brent Spence Bridge, which is in need of expansion in order to accommodate the increasing traffic flow:7
- Construct new I-75 bridge to the west of the existing Brent Spence Bridge and leave I-71 on the Brent Spence Bridge. With this option, I-71 and I-75 would not be merged for any distance in Ohio, and the Brent Spence Bridge (I-71) would be restriped for three lanes in each direction with full emergency shoulders.
- Construct two new bridges, one for I-75 (to the west of the existing bridge) and one for I-71 in place of the existing Brent Spence Bridge if it is determined that the existing span cannot be reconstructed/rehabilitated to modern Interstate safety standards.
- Build new I-75 bridge to west of Brent Spence Bridge and create an interchange with connections from the new bridge to both I-75 and I-71 in Ohio. The Brent Spence Bridge would remain in place, carrying Interstate 71 and local traffic only.
- Construct a new I-71/75 bridge with ten lanes in place of the Brent Spence Bridge, which would be demolished.
- Remove Brent Spence Bridge and replace it with two bridges side by side, one for I-75 through traffic and the other for through and local traffic along I-71.
- Construct a new bridge for I-71/75 to the west of the existing Brent Spence Bridge, and repurpose the Brent Spence Bridge for local traffic only.
The new bridge would be built west of the existing Brent Spence Bridge in order to avoid an electrical substation and historic Longworth Hall. These alternatives, released as part of a $2 million study, would take over a decade to construct once funding was made available. The Kentucky Transportation Cabinet (KYTC) aimed to refine the list of alternatives to two choices in 2005. Since Kentucky owns the bridge, it was thought the state would bear most of cost.7 Succeeding developments indicated that tolling the bridge might be necessary to secure funding and shorten the time table needed to replace the span. Details and the potential time line on the project found at the Brent Spence Bridge Corridor web site.
North from Cincinnati, an Ohio Department of Transportation (ODOT) project known as the “Thru the Valley Project” or North-South Transportation Initiative, focused on growing congestion along Interstate 75 from State Route 561 north through Warren County. 2003 estimates for the project included an option for new light rail, with $1 billion allocated to the stretch through Hamilton County.1,4 Preliminary studies and design work commenced in May 2004 to widen and reconstruct the freeway between Paddock Road and Interstate 275.
The roadways of Interstate 75 separate by up to a half mile through Lockland, Ohio. Southbound travels below grade at Exit 12 between Wyoming Avenue and Lock Streets. This view looks from the Wyoming Avenue overpass at the exit ramp to Cooper Avenue. 11/08/09
Due to cost increases and rising inflation in 2009, work on the Thru the Valley Project was separated into eight phases. Phases 1 through 3, including portions of I-75 between Shepherd Lane (Exit 13) and Glendale-Milford Road (Exit 14) and I-75 at SR 126 (Ronald Reagan Highway), were underway with property acquisition by 2016. Property acquisition for Phase 8 was to start in Summer 2016, followed by Phases 4, 5 and 6 in 2017. When completed, Interstate 75 expansion will bring the freeway to eight overall lanes, with added auxiliary lanes where needed.
The Thru the Valley Project phases from south to north:13
- Phase 3 – reconstruct the freeway between the Mill Creek bridge and the trumpet interchange with SR 126 (Ronald Reagan Highway) and add a fourth lane in each direction. Costing between $39-49 million, with work scheduled between
Spring 2020 and Fall 2021 Fall 2023 to Summer 2025.
- Phase 4 – replace the railroad bridge over I-75 southbound and realign Exit 10 to Galbraith Road. Costing between $22-32 million, work was previously scheduled to run from Spring 2020 through Fall 2021. A revised time table between Fall 2022 and Fall 2024 was subsequently put on hold.
- Phase 6 – add a fourth lane to Interstate 75 northbound while reconstructing the roadway from Galbraith Road to Shepherd Lane (Exit 13). Add a new ramp from SR 126 west to I-75 north. Construction on the $125-135 million project was previously anticipated from Spring 2022 to Fall 2024. The tentative schedule was revised to Spring 2027 to Spring 2030.
- Phase 5 – rebuild the southbound lanes of I-75 from Shepherd Lane to Galbraith Road (Exit 10), adding a new lane and constructing a collector distributor road for new ramps with parallel Anthony Wayne Avenue and Galbraith Road. Costing between $63-73 million, the time frame was revised from Spring 2020 to Fall 2021 to Spring 2024 to Spring 2025.
- Phases 1 & 2 – expanded I-75 to eight overall lanes during reconstruction from Shepherd Lane (Exit 13) north to Glendale-Milford Road (Exit 14). Reconstruct the interchange with Shepherd Lane and realign Neumann Way to the east of Interstate 75. The $90 million project broke ground in Spring 2017. Scheduled for completion in Spring 2021, it was previously anticipated to wrap up in Spring 2020, then Fall 2020.
- Phase 8 – adding capacity to the diamond interchange (Exit 15) with Sharon Road and Chester Roads, work also adds a fourth lane to I-75 in each direction while reconstructing the mainline from Glendale Milford Road north to Kemper Road (just south of I-275). Construction on the $46 million phase runs from Spring 2021 to Summer 2025.
Construction funding was not allocated for any of the phases beyond 1/2 as of June 2016. This remained the case through 2020, so time tables are subject to change.
The Downtown Dayton Sub-Corridor project between Edwin C. Moses Boulevard near Exit 52B (U.S. 35) and Keowee Street, near Exit 54B (SR 4) began in October 2007. The long term project separated into three phases:
Phase 1A included reconstruction of the interchange between I-75 and SR 4 to eliminated a sharp curve, rebuilding ramps or closing ramps and replacing left exits. Work included upgrading the Main Street exit and expanding the freeway mainline to six continuous lanes. The $122 million project ran through Fall 2011.
Phase 1B commenced in March 2010. It expanded I-75 to six overall lanes between Edwin C. Moses Boulevard (Exit 51) and the viaduct over 5th Street (SR 4) and rebuilt a portion of the four-level interchange with U.S. 35. The $58 million project was completed in Fall 2013.
Costing $126 million, Phase 2 connected the previous project areas by expanding Interstate 75 to three continuous lanes per direction. Crews also reconstructed 12 bridges and eliminated additional left entrances and exit ramps. Work ran from Spring 2013 to a completion ceremony held on September 22, 2016. Follow up work continued on U.S. 35 at the exchange with I-75. Separate but nearby projects replaced bridges for I-75 at Edwin C. Moses Boulevard and Wagoner Ford Road (Exit 57).12
Under a 10-year $5 billion transportation improvement plan announced August 6, 2003 by Governor Bob Taft, Interstate 75 was expanded from four to six lanes between I-475 (Exit 205A) and I-280 (Exit 208) and between 14th Street and Anthony Wayne Trail near Downtown Toledo. Additionally the exchange at I-75/475 (Exit 205A) was reconstructed and improved. A six cent hike to the state motor fuels tax over the course of three years helped cover the costs of these projects.5
Leaving the Buckeye State, Interstate 75 approaches the Detroit metropolitan area. Construction completed in July 2009 reconstructed the interchange with Interstate 96 as part of the Ambassador Bridge Gateway Project. Work started on February 25, 2008 improved the connection between I-75 and the Ambassador Bridge linking Detroit and Windsor, Ontario. I-96 eastbound was extended to beyond I-75 to the bridge into Canada, while the westbound connection remained incomplete due to a jurisdictional dispute between the Detroit Bridge Company and the Michigan Department of Transportation (MDOT).
Interstate 75 leaves Downtown Detroit with a northerly course toward the Upper Peninsula via one of the country’s longest suspension bridges, the Mackinac Bridge. The Mackinac Bridge is symbolic for connecting the Lower and Upper Peninsulas of Michigan. Spanning the Straits of Mackinac, this toll bridge crosses over waters that freeze in the coldest winters. The left lane of the bridge is steel grating rather than concrete. Mackinac Island, home of famous Mackinac Island fudge, can be reached by ferry from either Mackinaw City or St. Ignace.
Beyond Easterday Avenue (Exit 394) at Sault Ste. Marie, Michigan, Interstate 75 concludes at the port of entry for the International Bridge. With two overall lanes, the tolled arched truss bridge linking Sault St. Marie Michigan with Sault St. Marie, Ontario opened to traffic on October 31, 1962. The International Bridge Toll Plaza project replaced conventional toll booths with a new enhanced toll collection system. The two year long project cost $8.9 million and commenced in May 2014.