By Chris Wright, The News On 6

UNDATED -- Tulsa is testing its much-anticipated Enhanced 911 service for the first time this week. 

E-911 allows first responders to locate calls made from cell phones.  Other Oklahoma counties are already using E-911, and say it has saved lives.  That's left many people asking, what took Tulsa so long?

It's a process nearly four years in the making that is coming to fruition.  Dispatchers are testing E-911, which could be partially online by Friday and allow dispatchers to pinpoint where cell phone callers are.  It's a system that officials say could have helped this past weekend when a pickup plunged into a rock quarry, killing three.  It took first-responders two hours to find the lone survivor.

Counties such as Okmulgee, Mayes, Rogers and Wagoner have been using E-911 since as early as 2006.  The delay in Tulsa, says Ken White, is caused by many more cell phone towers, and more carriers it must deal with.

"In the city of Tulsa alone, just on AT&T towers, there is about 600 of them.  So, that's a lot of cell towers to test, and information that has to be programmed," said Public Safety Manager Ken White.

But E-911 has been up and running the state's most populated county for the past year.  Dispatchers in Oklahoma City say it is already paying dividends.

"We're able to pull up a satellite image and say that they're the third house on the left," said Oklahoma City dispatcher Sean Elsten.

"It's very crucial. We use it on a daily basis to find our callers in the Oklahoma City system," said Eric Callender with EMSA in Oklahoma City.

Despite the fact that Tulsa is playing catch-up, officials believe the wait will be worth it, and the system will save lives.    

"We know technology will continue to advance and we have to be able to keep up with that," said Public Safety Manager Ken White.

Everyone in Tulsa County has been paying a 50 cent a month surcharge for E-911 since March 2006.  If all goes according to plan, Ken White says AT&T users should be able to use E-911 by the end of the week.

A federal mandate requires all other carriers to be online within 90 days.