I'm trying to figure out if it is possible to create a Service Area layer that represents equal drive times between 2 facilities. I have Ambulance Base A and Ambulance Base B and I want the drive time from A to some point on the boundary to equal the drive time from B to the same point on the boundary line. This is not the same as creating a service area with a static drive time (eg 5 min). The drive times may change, but at any point on the boundary, the 2 facilities will share the same drive time. Hopefully I explained enough, and hopefully this is possible!
Bring up the properties of the service area layer and on the polygon generation tab there is a section for Multiple Facilities Options and you can click on the Not Overlapping method. This will split the overlapping areas between two facilities at equal distance (or time) and only generate the polygons along the equal distance line. More help here in the Multiple facilities options: