U.S. Route 23 in Florida

U.S. Highway 23
Route information
	Maintained by FDOT
Length:	37.656 mi (60.601 km)
Major junctions
South end:	US 1 / US 17 in Jacksonville
	US 301 in Callahan
North end:	US 1 / US 23 / US 301 towards Folkston, GA
Location
Counties:	Duval, Nassau
Highway system

U.S. Highway 23 (US 23) is a United States Numbered Highway that runs from Jacksonville, Florida to Mackinaw City, Michigan. In the U.S. state of Florida, US 23 is concurrent with US 1 south of Alma, Georgia, except in Downtown Jacksonville. US 23 is also concurrent with US 301 between Homeland, Georgia and Callahan. In the Jacksonville area, US 23 is the unsigned State Road 139 (SR 139), which also continues east from the south end of US 23 along SR 10A to SR 115 near the Mathews Bridge.

Route description

U.S. Route 23 begins at US 1 (Main Street) at the northern end of downtown Jacksonville, starting as a one-way pair, with the northbound lanes meeting with Florida State College. It is also unsigned SR 139 from its southern terminus to its interchange with US 1 in northwestern Jacksonville (SR 139 continues east along SR 10A from the end of US 23 to SR 115). West of I-95, US 23 ends the one-way pair, continuing as Kings Road through northwestern Jacksonville, as an off-grid road. A few miles to the west, US 23 meets with US 1/SR 15 (Martin Luther King Jr. Parkway), running concurrently with the highway through the rest of its journey through Florida. The road continues northwest, intersecting with Interstate 295 (I-295) and eventually makes its way out of Jacksonville. At Callahan, US 1/US 23 meets US 301, beginning a three-way concurrency as the road continues northward towards the St. Mary's River, leaving Florida and entering Georgia.

History

A US 23 shield used in Florida prior to 1993

US 23 was extended into Florida in about 1950.

Major intersections

County	Location	mi^[1]	km	Destinations	Notes
For the rest of SR 139, see SR 10A (mile 1.24-0.000)
Duval	Jacksonville	0.000	0.000	US 1 / US 17 north / SR 228 east (North Main Street / SR 5) East Union Street (SR 10A east / SR 139 south)
		0.093	0.150	US 90 Alt. west (North Laura Street)
		0.688	1.107	To I-95 / US 90 (Beaver Street) / North Davis Street
		0.84	1.35	I-95 / US 17 south / SR 228 west (SR 9) to I-10 west	I-95 exits 353B-C; north end of US 17 / SR 228 overlap; no direct access from US 23 south to I-95 north (turn around at North Davis Street)
		3.820	6.148	US 1 south (M.L. King Jr. Parkway / SR 15) to I-95	Interchange; no southbound entrance; north end of SR 139 overlap; south end of US 1 / SR 15 overlap
See US 1 (mile 511.20-545.03)
Nassau	Boulogne	37.656	60.601	US 1 north / US 23 north / US 301 north / SR 4 north / SR 15 north – Folkston, Nahunta, Waycross	Georgia state line (St. Marys River bridge)
1.000 mi = 1.609 km; 1.000 km = 0.621 mi Concurrency terminus