The Department of Home Affairs says an exercise has simulated a major incident on the roads.
It involved a fake car crash outside the Vehicle Test Centre in Tromode, and saw all the Island's emergency services responding.
Injured people were played by medical students who wore realistic makeup.
The government said it allowed emergency teams to train in triage and moving casualties.
Company wants your views on Island travel links
Are you ready for emergencies?
Taxpayers' Alliance company dissolved
MHK queries Peel Promenade closure
Chamber of Commerce offers budget breakfast with minister
Bill reminder for manx.net email changeover
Dangerous trees question tabled by MHK
Council sees drop in rates arrears