Interstate 75 (I-75) is a major Interstate Highway in the Great Lakes and Southeastern regions of the United States. As with most interstates that end in a five, it is a major cross-country, north-south route, one of the longest in the U.S., from southern Florida to the northern tip of Michigan. It travels from State Road 826 (Palmetto Expressway) and State Road 924 (Gratigny Parkway) on the Hialeah–Miami Lakes border (northwest of Miami, Florida) to Sault Ste. Marie, Michigan, at the Ontario border. Interstate 75 is the seventh longest interstate highway, the second longest north-south after Interstate 95, and passes through six different states: Florida, Georgia, Tennessee, Kentucky, Ohio, and Michigan.

Due to high traffic levels on the Interstate, much of the route is six lanes even in rural areas.

Route description

Florida

Interstate 75 (I-75) is a part of the Interstate Highway System and runs from the Hialeah–Miami Lakes border, a few miles northwest of Miami, to Sault Ste. Marie in the Upper Peninsula of Michigan. I-75 begins its national northward journey near Miami, running along the western parts of the Miami metropolitan area before traveling westward across Alligator Alley (also known as Everglades Parkway), resuming its northward direction in Naples, running along Florida's Gulf Coast, passing the cities of Fort Myers, Punta Gorda, Venice, Sarasota, and the Tampa Bay Area, before turning inward towards Ocala, Gainesville, and Lake City before leaving the state and entering Georgia. I-75 runs for 471 miles (758 km) in Florida, making it the longest interstate in any state east of the Mississippi River. The interstate maintains a speed limit of 70 mph (110 km/h) for its entire length in Florida.

The portion of I-75 from Tampa northward was a part of the original 1955 Interstate Highway plans, with I-75's southern terminus at I-4's current western terminus. Planning to extend the interstate south to Miami began in 1968 after massive growth in Southwest Florida, which resulted in I-75 being realigned to travel on the eastern fringes of the Tampa Bay area, and the last portion of the highway was opened in 1993.

Interstate 75 (I-75) runs from Cincinnati to Toledo by way of Dayton in the U.S. state of Ohio. The highway enters the state running concurrently with I-71 from Kentucky on the Brent Spence Bridge over the Ohio River and into the Bluegrass region. I-75 continues north into the Miami Valley and then passes through the Great Black Swamp before crossing into Michigan.

Route description

In Cincinnati, approximately 17 miles (27 km) of the highway will be totally reconfigured by three separate ODOT projects happening simultaneously. The Brent Spence Bridge Corridor project will replace the Brent Spence Bridge and continue north to the Western Hills Viaduct. The Mill Creek Expressway project will modernize the Mill Creek Expressway segment of the highway, from the Western Hills Viaduct to the Ronald Reagan Cross County Highway interchange. The Thru the Valley project will continue from the Reagan Highway north to Interstate 275. These projects will improve safety by eliminating all left-hand exit ramps and increasing vehicular capacity.