Order: priority vehicle - priority road - same level (right road is empty - right - go straight - left):
1. Police car because it is a priority vehicle<9 >2. Trucks because they are on priority roads
3. Passenger cars because they are on non-priority roads, turn left and the right side of the road is empty first (because police cars run first)<9 >4. Car because it's on a non-priority road, turn left and right side of the street, the car is empty after (because the passenger car is following)