The crash happened after 10:00 a.m. Thursday near mile marker 181.5 in Upper Providence.
Police say Diane DeCarlo, 65, of Douglassville, Pa. was changing lanes when she lost control of her 1996 Lincoln Continental sedan.
The car slammed into a PennDOT dump truck parked on the right shoulder of the road.
DeCarlo and a passenger, 87-year-old Vincent John DeCarlo, also of Douglassville, were taken to Paoli Hospital in stable condition with non-life-threatening injuries.
The driver of the PennDOT truck, 53-year-old John DeMichael, Jr. of Barto, Pa. was not injured.
All eastbound lanes of Route 422 were closed at Township Line Road at the Royersford Interchange until 12:15 p.m. as crews worked to clear the wreckage.