Traffic was slow on the northbound Interstate 45 near Woodlands Parkway after a crash about 11:50 a.m. Friday.
Two lanes were temporarily blocked, according to Houston TranStar.
Another crash jammed the outbound South Freeway near Holmes, temporarily blocking two lanes.
Earlier, the North Loop in northeast Houston was clogged after a crash about 8:20 a.m. in the eastbound lanes near Kirkpatrick.
Two lanes on both the eastbound and westbound North Loop were temporarily blocked.
The East Loop had problems earlier after a four-car pileup briefly brought traffic to a standstill near the Houston Ship Channel.
The wreck happened about 6:20 a.m. on the southbound East Loop near the Port of Houston, according to Houston TranStar, and crews cleared the scene by 6:41 a.m.
All southbound lanes were blocked while crews cleared the scene. The lanes were later reopened.
No information was available about possible injuries or what caused the crashes.