SH 342 begins  at a junction with US 77 in Red Oak. It heads north from this junction to two other intersections in Red Oak, FM 2377 (locally known as Louise Ritter Boulevard) and FM 664 (locally known as Ovilla Road).
SH 342 begins at an intersection with US 77 in Red Oak. It then moves north to two other significant intersections in the town, FM 2377 (locally known as Louise Ritter Boulevard) and FM 664 (locally referred to as Ovilla Road).