What could/should members of the public do when the alert level is raised or lowered? | National Coordinator for Counterterrorism

What could/should members of the public do when the alert level is raised or lowered?

The public is not expected to do anything. Remain alert to unusual situations as is usually requested. The Counterterrorism Alert System is intended for the professional services (e.g. the police) and certain economic sectors. They will take action if this is required.  The public will be informed if it is likely that it will be inconvenienced by the measures taken.