A survey of Florida highway rights-of-way was conducted during 1984–85 to determine the occurrence and severity of cogongrass infestation. Florida Department of Transportation district maintenance engineers surveyed 8,200 km of limited-access and other major highways (22% of highway system). Cogongrass was distributed widely from the north central region southward through the central Florida ridge north of Lake Okeechobee. Highest frequencies were in counties where cogongrass was used for forage and soil stabilization during the 1950s. The large, widely scattered cogongrass infestations probably were established during extensive roadway construction and routine maintenance which used rhizome-contaminated fill soil.
