Callahan, Florida
Transportation
### Transportation

#### Roads

Callahan lies at the intersection of [US 1](/wiki/U.S._Route_1_in_Florida "U.S. Route 1 in Florida"), which is also part of [US 23](/wiki/U.S._Route_23_in_Florida "U.S. Route 23 in Florida") as well as [US 301](/wiki/U.S._Route_301_in_Florida "U.S. Route 301 in Florida"), the northern terminus of [Florida State Road A1A](/wiki/Florida_State_Road_A1A "Florida State Road A1A") and [Florida State Road 200](/wiki/Florida_State_Road_200 "Florida State Road 200"). US Routes 1 and 23 run together northbound in an overlap from the Grand Park section of Northwest Jacksonville through the [St. Mary's River](/wiki/St._Marys_River_%28Florida/Georgia%29 "St. Marys River (Florida/Georgia)"). US 301 joins US 1 and 23 from an overlap with hidden State Road 200, that begins as far south as [Ocala](/wiki/Ocala%2C_Florida "Ocala, Florida"). SR 200 itself joins a wrong way concurrency with SR A1A into [Fernandina Beach](/wiki/Fernandina_Beach%2C_Florida "Fernandina Beach, Florida"). [Florida State Road 115](/wiki/Florida_State_Road_115 "Florida State Road 115") runs from the Deercreek section of Southeast Jacksonville and terminates with US 1 and 23 south of downtown, but contains a de facto extension at the northern edges of town in the form of CR 115 on Kings Road and Old Dixie Highway. CR 108 is known as North Brandies Avenue then becomes Saint George Road as it loops around western Nassau County then curves to the east while passing through Hillard where it runs through another intersection with US 1, 23 and 301\. The road continues east through northern rural Nassau County briefly passing through Evergreen, and finally terminates at US 17 north of Becker.

#### Railroads

Two railroad lines exist within Callahan; The [CSX](/wiki/CSX "CSX") [Nahunta Subdivision](/wiki/Nahunta_Subdivision "Nahunta Subdivision"), a former [Atlantic Coast Line Railroad](/wiki/Atlantic_Coast_Line_Railroad "Atlantic Coast Line Railroad") line which runs from the Jacksonville Terminal Subdivision in Jacksonville to the Savannah Subdivision in [Savannah, Georgia](/wiki/Savannah%2C_Georgia "Savannah, Georgia"), and the [CSX](/wiki/CSX "CSX") [Callahan Subdivision](/wiki/Callahan_Subdivision "Callahan Subdivision"). a former [Seaboard Air Line Railroad](/wiki/Seaboard_Air_Line_Railroad "Seaboard Air Line Railroad") line which runs south to a junction in Baldwin that includes the [Wildwood Subdivision](/wiki/Wildwood_Subdivision "Wildwood Subdivision") the former [Tallahassee Subdivision](/wiki/Tallahassee_Subdivision "Tallahassee Subdivision") and another leg of the Jacksonville Terminal Subdivision. Two former SAL lines that extended from the Callahan Subdivision were an abandoned segment of the [Fernandina Subdivision](/wiki/Fernandina_Subdivision "Fernandina Subdivision") and the [Gross Cutoff](/wiki/Gross_Cutoff "Gross Cutoff").


Which US routes run together northbound in an overlap from Grand Park to St. Mary's River?