A main route through mid Wales was closed in both directions following an accident in the early hours of Monday.
The A470 between Rhayader at the B4518 and Llangurig at the A44 in Powys was shut to allow Dyfed-Powys Police to work in safety while it recovered a vehicle involved in the incident.
The force reported icy conditions on the road following wintry weather overnight and said the road was likely to be closed for a number of hours.
Diversions were put in place.
The accident involved a lorry, a spokeswoman said.