The A472 was closed due to an accident involving five vehicles – including a jackknifed lorry.
The road had been blocked between the Brynmynach Avenue junction and the Heol Fawr junction – it is just one of several incidents.
The crash happened at 6.10am this morning near Tredomen Business and Technology Centre – vehicles involved were a lorry, Grey Ford Ranger, Black Ford Focus, Red Audi A3, Red Ford Mondeo.
Police said two people were taken to hospital as a precaution.
Caerphilly Road in Llanbradach was also closed both ways between Wingfield Terrace and Duffryn Industrial Estate because of ice and an accident involving two vehicles.
The A469 New Road in Bargoed was also partially blocked for a time after a crash involving several vehicles near Pengam Road.