Due to increasing traffic, State Road 80 has experienced upgrades and widening in various sections since 2000.

[3] From here, it is known as Palm Beach Boulevard, a four-lane divided highway that parallels the Caloosahatchee River.

Lion Country Safari marks the beginning of a rural to suburban and later urban transition of the road for the remainder of its journey.

It then approaches a bridge over the Tri-Rail main line as it intersects Interstate 95 at Exit 68, then becomes a four-lane road in several older, high-density neighborhoods in West Palm Beach.

East of the Florida East Coast Railway bridge crossing, it intersects US 1 and SR 5, reducing to two lanes as it crosses Lake Worth Lagoon on two bridges, and ending on a roundabout with SR A1A in Palm Beach near the Mar-a-Lago estate.

[8] The section from Twenty Mile Bend to West Palm Beach was considered part of the Conners Highway, which opened on July 4, 1924.

[9] The route was first designated State Road 25 in 1923, running from Palm Beach to Punta Rassa.

[10] The segment between Belle Glade and Twenty Mile Bend, designated as the Kenneth C. Mock Memorial Highway was completed in 1989, making SR 80 a four-lane divided highway between Belle Glade and West Palm Beach.

Until 2002, Palm Beach County's Southern Boulevard was a four-lane road with a center left-turn lane, causing high gridlock due to the rapidly growing western suburbs of Loxahatchee, Royal Palm Beach and Wellington.

[13] In 2002, after many years of debate, the Florida Department of Transportation embarked on a $78 million project to upgrade and widen Southern Boulevard from I-95 to US 441/SR 7.

[12] Between 2003 and 2008, it was transformed into a limited-access highway with freeway-grade diamond interchanges at the most congested intersections, with traffic signals remaining at others.

[14][15] In Hendry County, a project to improve the intersection between SR 80 and US 27 and add an overpass was completed at the end of 2014.

This widening eliminated the last two-lane undivided segment of SR 80, and it is now at least four lanes from Fort Myers to West Palm Beach.

[20] SR 80 between Monroe and Fowler Streets was relinquished to the city of Fort Myers on January 11, 2006 as part of the downtown redevelopment and streetscape effort, which first created the gap in the route that exists today.

[3] The City of Fort Myers restored the remaining one-way segments of First, Second, and Seaboard Streets to two-way traffic in June 2022.