The A34 was closed northbound overnight after a vehicle reportedly overturned in a crash.
The dual carriageway was shut between the junction with the M4 at Chieveley and the A4185 at Chilton.
It followed a crash on the road. National Highways, which advised drivers to take a detour to avoid the closure, said a vehicle had overturned.
The road was back open by 6.30am this morning (Saturday, June 10).