I think it would be both practical and realistic to add an addition setting to the back up menu. In addition to code 2, code 3, and pursuit it would be cool to request units into the scene. For example, call comes over for shots fired, and of course you have to drive up onto an overpass, cross a bridge and jump through some hoops to make it to the scene, this cat could be getting away with some murders under his  belt!!! So you pull up the trusty dispatch menu, select code 3 (I suppose 2 as well? Why not) you scroll down to the unit your requesting code 3 (local, state, swat, ect.) then once that unit is highlighted the player can have the option of "my location" or "to scene" that way when selecting to scene your backup heads to where they are actually needed even if you are not already on location. Of course using the "my location" will still traditionally ssend them to where the player is standing when making the request as LSPDFR currently does.

I like this idea. Perhaps another way of doing this could be to set a waypoint on the map and have units sent there? 

Yeah it's unrealistic to be the only cop responding to a hold up/robbery, etc.

i to like this idea!