I don't understand the issue over installation of WIFI, surely all you do is go out to the telecoms market and say...
"How much are you willing to pay us for the benefit of a captive WiFi market?"
Unless, of course, the "paradigm" has changed now that you can buy a cheap dongle or connect your laptop/device to your mobile without bothering about a potentially insecure public connection.
In which case WiFi on public transport is about as useful as a telephone in a hotel bedroom.