While search for a way to visualise flows between schools and universities in England, I came across this excellent bit of software by Doantam Phan et al from Stanford: Flow Map (paper). It was presented at Infoviz 2005.
It’s a Java application, simple to install, and with the addition of an appropriately formatted data file, you can have a flow map up quickly. The software allows points to be moved around to declutter the visualisation – allowing a good balance between geographic accuracy and clarity.
Here’s the English universities that Southend-on-sea school pupils choose to go to – N and W England cropped out for simplicity:
London and the other multi-university cities are “exploded” but the universities retain their geographic equivalence.