Make it really easy to get to the airport.<p>Pro: Airport parking is an expensive hassle, thus people are always taking cabs or asking for rides. Airports are far from city centers, and often inconvenient to get to.<p>However, it's probably not enough traffic to sustain an entire system, but I think it makes for a good first step in a new system.<p>The other thing is that we either need to:<p>1) Stop subsidizing air &#38; road travel so much<p>2) Subsidize public transit in order to make it more competitive with road / air travel<p>#1 is politically infeasible ... but perhaps #2 is as well. Maybe public transit support could be billed as a way to get everyone else off the road?