The core rule
Emergency vehicles with blue lights + siren have absolute right of way. You are obliged to immediately clear their path, normally by moving right and stopping if necessary.
What to do when you hear a siren or see blue lights — and what NOT to do.

Emergency vehicles with blue lights + siren have absolute right of way. You are obliged to immediately clear their path, normally by moving right and stopping if necessary.
1. Signal right 2. Move right, give as much space as possible 3. Stop if needed for the emergency vehicle to pass 4. Wait until it has passed before continuing On motorway: form a rescue lane, left-lane vehicles move left, everyone else moves right, creating a corridor in the middle.
• Follow the emergency vehicle in its route (e.g. exploiting the gap it creates): prohibited, dangerous • Brake hard without checking the mirror, the car behind may not stop in time • Block a junction because the emergency vehicle is 'far away'. It can arrive faster than you think • Run a red light to move out of the way, only move to a legally-reachable spot
Emergency vehicles with just blue lights (no siren) are not in emergency mode. They have NO special priority. Follow normal traffic rules; give way if easy but you are not obligated.