It's always going to be hard to fill gaps, but locating them is a key first step.
New York City and California have begun to offer up their GIS files to anyone who wants them, and early results are amazing.
California affirms that cities can't withhold digital mapping information.
How does where we live affect our health? An expert tries to quantify it.
A new report uses reams of data to design a better transportation system.
Researchers have developed a GIS-based technique to keep track of skyline changes.