Last week, on my way back from Omaha (where the Union Pacific, the railroad for whom Dodge did the surveying, is based) I ran across a Navteq survey SUV near Alta Vista, Kansas.
Today, surveying is quite a bit easier. They use a large, and highly precise, GPS antenna and combine it with six cameras in the dome. The GPS signal is linked to the photos and everything is digitized.
You can read details of the process here.