Like explorers from centuries past, Molly McLain and Kim Moss navigate the unknown, compiling reliable directions and maps along the way. But for these two Navtech employees, GPS is their compass, a computer database their canvas. And instead of charting some remote coastline, these digital mappers help you make it through the urban wilderness of cities such as Chicago.

Join me tonight on "Tech Live" to see the human element behind getting your driving directions online. What, you thought there was some magical directions fairy?

Navigation Technologies (Navtech) is the service behind MapQuest, Yahoo! Maps, and OnStar, to name a few. The company employs more than 1,300 people across the United States. Field agents such as McLain and Moss drive the streets mapping new roads and making sure driving directions are correct and current.

Mapper for a day

I recently navigated through Chicago to meet mappers McLain and Moss. McLain's a geography major and Moss is a geek who assimilates all the data they collect into the Navtech database. That particularly windy day's destination was the newly reopened Soldier Field.

"They've just finished a ton of construction" McLain says. "So we're guessing that there are new streets that we don't have right in the database."

As soon as we turn off Lake Shore Drive, Moss recognizes an anomaly.

"This is very confusing. We're gonna have to drive it. I think these signs have blown, so why don't we take a right and see what those signs say," she says.

Tools of the trade

A little green arrow on Moss' laptop screen mirrors our movement. Her laptop connects to a GPS unit anchored to the roof of the car. Moss manipulates the laptop with a Wacom Tablet and pen.

"I use the pen tool to write down names of roads or explain any significant changes to what we currently have in the database," she says.

Moss opens up a "Shmem," or shared memory file, and puts in all the new info. When she gets back to the office, the heavy lifting starts.

"Usually it takes about twice the time to code it as it does to drive," Moss says. "There's so much information to put in."

Dynamic duo

McLain helps keep track of where they've been and where they need to go, but she says she's best behind the wheel.

"Personally I don't have a very good sense of direction. I just get lost even if I have a map," she says.

When asked if being directionally challenged makes her the perfect candidate for this job, she's very enthusiastic.

"I know what the most confused driver needs to know," she says.

The two make a good pair. Moss says she never gets lost, and they seem to have a good time on the road. McLain especially relishes the fact that people are curious about their actions.

"With all this gear on the car, they think we're storm chasers or from the mosquito abatement program," McLain says.

"The cops have pulled one of our co-workers over," Moss adds. "People in the neighborhood he was mapping saw him driving back and forth. They thought he was casing houses."

So the next time you get a map online that's not quite right, know that people like Moss and McLain are on the road trying to make it better.