score:3
You may be interested in OpenFlights.org. There's a great blog post on it here:
and that was several years ago, it's come in in leaps and bounds since.
It doesn't quite describe what you're after (as far as I know) but it's pretty powerful in seeing which routes go from which airport.
Eg, type in MEL, select Melbourne Airport.
Click second icon to see all routes from this airport.
136 routes ex-Melbourne, all displayed on the same map.