Wessex Way in Bournemouth was closed on Tuesday evening because of a welfare incident.
Dorset Police says it received a report at around 7.20pm and officers attended the scene, where they located a teenager and arranged for them to be taken to hospital to receive the “appropriate care”.
Closures on the A338 were introduced while emergency services dealt with the incident, with police saying the restrictions were needed for the safety of everyone involved on the busy route through Bournemouth.
The closures remained in place for just over an hour, before Dorset Police confirmed the A338 had reopened at around 8.35pm and traffic was able to use the road again.
No further details about the teenager or the circumstances leading to the welfare concern have been released.
