How Airports Serve Indiana
Mark Pearson
This map displays the major airports in and around Indiana. It shows how the state can divided according to which airport is the closest as the crow flies.
The flags are a sample of 500 census tracts (of 1507 tracts total) within the state.
Some census tract flags may look like they are colored for one airport's region but are actually in another airport's region. The census tract flags are colored with which airport they are closest to as the crow flies along the surface of the earth (the Haversine distance formula). The region boundaries that are displayed on map were computed assuming assuming the earth is flat. (The lines that divide regions are a Voronoi diagram, and I couldn't find any algorithm that calculate the lines on a sphere such as the earth.) In short, although a few census tracts may look like they're mislabeled near a boundary, it's actually the boundary that is slightly wrong.
For more information, see the full report:
http://www.mark-pearson.com/airport-distances/

IND serves 2,860,522 people in IN
Indianapolis International Airport

FWA serves 971,078 people in IN
Fort Wayne International Airport

SBN serves 801,652 people in IN
South Bend Regional Airport

MDW serves 651,924 people in IN
Chicago Midway International Airport

EVV serves 476,180 people in IN
Evansville Regional Airport

SDF serves 394,378 people in IN
Louisville International Airport (Standiford Field)

CVG serves 197,744 people in IN
Cincinnati/Northern Kentucky International Airport

DAY serves 96,373 people in IN
James M. Cox Dayton International Airport

AZO serves 31,625 people in IN
Kalamazoo/Battle Creek International Airport

BMI serves 2,326 people in IN
Central Illinois Regional Airport at Bloomington-Normal

dividing line

3,531 people
closest airport: EVV

6,444 people
closest airport: MDW

3,884 people
closest airport: SDF

closest airport: IND

closest airport: MDW

closest airport: EVV

closest airport: CVG

closest airport: FWA

closest airport: SDF

5 people

closest airport: SBN

closest airport: DAY

81 people

664 people

closest airport: AZO

closest airport: BMI