While routes for Florida state roads are assigned by the Florida Department of Transportation (FDOT), county roads numbers are assigned by the counties, with guidance from FDOT.

[4] Both segments of CR 68 and SR 68 are part of the historical Florida Cracker Trail.

County Road 603 is Johnson Road west of Lakewood Park, from CR 607A north to the Indian River County line, where it continues north as CR 611.

The section north of SR 611 has a posted speed limit of 55 miles per hour (89 km/h).

County Road 615 is a southern extension of SR 615 along 25th Street, St. James Drive, and Airoso Boulevard, from CR 611 (Edwards Road) in Fort Pierce to SR 716 (Port St. Lucie Boulevard) in Port St. Lucie.

[4] County Road 709 is the designation of Glades Cut Off Road from its intersection with CR 613 west of Port St. Lucie northeast to CR 611B in Fort Pierce.

The roadway parallels the South Central Florida Express, Inc., rail line for its entire length.

North of Midway Road, CR 709 provides access to, among other industries, Tropicana's Fort Pierce juice processing plant, the St. Lucie County Landfill, and a Walmart Distribution Center.

The western terminus is an intersection with Okeechobee Road (SR 70) west of Port St. Lucie; the eastern terminus of CR 712 is an intersection with Indian River Drive (CR 707) on the western edge of the Indian River near Indian River Estates.

Since then, the growing population of Port St. Lucie has resulted in increased urbanization along much of the route, with Midway Road between US1 and Selvitz Road being widened from a two lane roadway to a four lane divided highway.

Both spurs lost their signage and their places in the road maps in the mid-to-late 1990s.