The air ambulance landed on the M56 near Chester where the carriageway was blocked in both directions following an accident.
Cheshire Police said initial reports indicated a collision involving three vehicles including a motorcyclist on the eastbound carriageway between J14 A5117 (Hapsford) and J12 A557 (Runcorn).
The accident was reported around 5pm. The condition of any casualties is not known at this time.
There was queueing traffic and the carriageway was blocked with congestion back to J15 at the intersection with the M53.
Travel website Inrix said traffic was temporarily held westbound to allow the air ambulance to land.
However, all lanes of the carriageway had been reopened to traffic by 6.30pm.