A car crash on the A404 near Maidenhead held up early-morning rush hour traffic after a person was taken to hospital.
They were treated at Wexham Park in Slough with minor injuries.
A spokeswoman for South Central Ambulance Service said it was called out at 7.47am.
Eyewitnesses on the A404 northbound said traffic had not moved for 40 minutes.
It is believed the crash was on the northbound carriageway, near the junction for Hurley.
Highways England said both the northbound and southbound routes were heavily congested.
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