A primarily rural route, LA 43 connects four small municipalities in Livingston and St. Helena parishes, including Springfield, Albany, Montpelier, and Greensburg.

LA 43 entirely parallels the Interstate 55 (I-55) corridor, located between five and ten miles (8.0–16.1 km) east in neighboring Tangipahoa Parish.

The route heads north through an area known as Hungarian Settlement and passes through an interchange with I-12 at exit 32, connecting with the cities of Hammond and Baton Rouge.

Immediately north of this junction, LA 43 crosses the Canadian National Railway (CN) line at grade.

Traveling along Sitman Street, the route passes the parish school board and clerk of court buildings.

Daily traffic volume in 2013 peaked at 12,300 vehicles in Albany with the remainder of the route averaging less than half that number.

LA 43 was created in the 1955 renumbering, giving a dedicated route number to the north–south corridor in Livingston and St. Helena parishes west of US 51.