Can you create service areas without facilities?

[JoshSaad1]

Our county's Mosquito Control division has asked us to update thier fog zones so that they accurately represent areas that can be driven for three hours, going fifteen miles per hour.  All of their vehicles are dispatched from a single location, but they don't need to restrict their travel time until they reach their assigned zone where they start and stop spraying.

Is it possible to create non-overlapping service areas without using facility locations?  Kind of like a tessellation, but instead of equal areas of land, it would be area in a road network by travel time.

[DavidPike]

I kind-of get it conceptually but (in my opinion) it makes very little sense and would be misleading at best.  

[JoshSaad1]

So, our drivers only have enough chemical to spray for three hours, driving at fifteen miles per hour.  They would drive normally until they reach their zone, then follow their route where they begin spraying. 

You could consider the point where they enter their zone as functioning like a facility, but I wouldn't know where to place that point without knowing the area of the zone. 

I need to divide the area of my road network into equal zones based on the distance that can be traveled in the alotted time.

[BruceBurwell1]

I am having the same problem. I won’t to create optimum service areas covering an area to make the minimum amount of patrol zones based on travel time. Basically, non overlapping trade areas. Is this possible or just trial and error?