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.

£20 million regeneration Plan submitted to the UK Government
Popular Barry Island Chippy announces its closure
Missing Penarth man found after appeal
Parc prison expansion plan ''ill-judged''
Panto stars drop in at Penarth hospice
Ruth and Steve go training with the RNLI
Aberthaw: trespassing banned at power station
New trains coming to Vale line in 2026
Council approves next step in Crossrail scheme
Aberthaw turbine donated to aviation museum
Council publishes 2025 self-assessment
Calls to ‘eliminate’ small business rates rejected
Lifeboat crew commended after complex rescue
Cladding repairs 'nowhere near acceptable pace'
More council cash in budget deal
Council boss joins CCR Energy
Senedd backs bus shake-up
Labour and Plaid strike £300m budget deal