Smart 911 (Enhanced 911 in many states) is designed to locate a cell phone within 100 feet and route it to the call center for that location. It was mandated (and you pay for it with every cell phone bill) to be effective about a dozen years ago. Regulators have pushed it back year after year and we're still looking at 4-6 years before it's reliably available, even though your phone can be located within 50 feet by your cell company.
Currently, the call is normally routed to the call center handling the tower it hits. All call centers can route your call to other local centers within seconds, so it's almost a non issue as far as call center routing. The response usually goes like this:
911 Operator: "911, can you tell me your location?" (Locations from land lines will show on their computer screens)
Caller: "I'm at the corner of 92nd and main."
911 Operator: "Please hold for the correct agency, do not hang up." (Operator hits ring-down key to correct agency)
911 Operator to New Operator: "I have a call for your jurisdiction coming from 92nd and Main."
New Operator to Caller: "911, what is your emergency?" (Call would start here from a land line)
Jeff