The driver in one of the crashes didn't stop to help, according to Houston police.
In southeast Houston, police said a woman was walking across the feeder road in the 3500 block of the I-45 Gulf Freeway when she was hit and killed.
The driver who hit her kept going, HPD said.
Investigators did not initially have a suspect vehicle description because they said they did not have video footage and no witnesses had come forward.
In northwest Houston, a woman was attempting to cross Hempstead Road near Perimeter Park Drive when she was run over and killed, according to HPD.
Police said the driver, who did not show any signs of intoxication, stayed at the scene and is cooperating with police.