My suggestion is to add a possibility to directly select a vehicle (click on the vehicle just like when it's status 3 or 4) that is returning to base and alarm it to go to marked place by using positioning tool (T) or just by using right-mouse button.
I know you can alarm it by order menu but when you have 5 or more incidents, you have to act fast because there are 3 places burning and you have 1 second to alarm the vehicle that is driving by a person that needs to be quickly stabilized/healed when the ambulance is far away, it can be sometimes difficult to get all incidents under control.
I understand it may be difficult to program this function but I'll be happy if you guys could consider this idea, thank you