The Barry Docks link road was closed following a two-vehicle collision on Wednesday night.
South Wales Police said the accident involved a red Vauxhall and a grey Nissan on the A4231 at just before 10pm.
No one was seriously injured but the occupants of both vehicles were taken to hospital for treatment.
The road was shut both ways for around three hours between the roundabouts for Port Road East and the Lidl supermarket.
There are no further details.