Can bicycling replace 50% of driving?

First, some background. A reader offered this reference and suggested that "they reckon half the trips in america can be done in a 20 minute ride."

So, can bicycling replace 50% of driving?

Not really. First, 50% of US trips may be short enough for a bicycle, but....they're very short trips..and would only account for a relative small% of miles traveled. Second, I don't see a real analysis of how many of those trips could truly be handled by bicycles: many trips involve multiple people, large loads, bad weather, or physically limited drivers for whom bicycles will never be appropriate. I couldn't find how they calculated the 50%, but if we assume that it corresponds to their best-case scenario for bicycling market share, we're talking about 8% of miles driving, of which half (or 4%) is probably realistic. If these are slow urban miles that are more energy intensive than average, maybe 5% of fuel consumption.

Bicycling is A Good Thing, but it's not the main solution. The main (fast) solution is replacement of oil with renewable electrity, mostly in transportation, which in turn is mostly light vehicles, starting with hybrids, moving through plug-in's (for a long time), and ending with EV's.

I'd like to see a real analysis of bicycle safety vs driving; and what it would take to provide real safety; and comparison of various solutions, including lanes, boulevards* and truly separate bike roads. I think we should expand bicycling (and electric bikes, and segways), but it will take a while to do properly.

*“bicycle boulevards,” typically residential streets where traffic volume and speed are reduced to levels at which bicyclists, pedestrians, and motorists can comfortably share the road.