E-assist bikes have already been mentioned but aside from that no one has really talked about technology and potential improvements to human powered transport.

Even existing things like trikes or recumbents can make long distance commutes faster and more comfortable. I know some people don't like how low to the ground they are, but if the infrastructure were safe enough that could alleviate some concerns.

Then there are velo-mobiles that could help people manage in poor weather.

There are lots of ways that bike performance could be enhanced but our performance bikes tend to come from the racing world where design is very much limited by UCI rules, - which are based on tradition as much as anything else. For example, racing bikes still have seat stays and seat tubes only because rules require them, - modern construction techniques don't.

I guess what I'm saying is that when thinking about what is realistic in terms of bike commuting, we shouldn't limit ourselves to only consider bikes as we normally think of them. We may be able to cover more ground in less time and perhaps even in more comfort if we look beyond traditional bikes.