Excerpts from WGNtv.com:

Most callers assume 911 operators receive address information automatically when they call. That’s the case with landline phones but not cellular calls. 

“We have to explain to [callers] that we need to verify their address because with cell phones, we don’t get an exact address,” said Chicago 911 dispatch trainer Sherrie Y. Wright.

Why can Uber and other apps pinpoint your location when 911 can’t? That’s because apps use GPS information you agree to provide and transmit. 911 relies on cellular carriers to report a caller’s location. The carriers do that by determining the location of the cell tower with which the phone connects. It means 911 dispatchers can initially receive an address range of several blocks but they can “re-ping” the phone which usually narrows it down to a single block, but often doesn’t provide a specific street address to send help.

Right now, the FCC has an agreement with the big wireless carriers: They only need to transmit specific street addresses 40-percent of the time. That number is slated to increase to 80% of calls by the year 2021. 

Despite the fact wireless phone users in Illinois are paying as much $3.90 per month in 911 surcharges,  Illinois lawmakers diverted $7.5 million in 911 fees to shore up the state’s general revenue fund in recent years.

Private firms have developed apps and other software that will relay the specific location of wireless callers, but it comes with additional cost.

Chicago 911 officials say the best way to help first responders emergency personnel to reach you in an emergency is to quickly and clearly state the location from which you’re calling.

thanks Dan