You know, one other possibility is that maybe not everybody has a bicycle in Paris. In the USA, it seems that everybody has a bicycle - many unused, of course. However, when I visit Europe, it occurs to me that there is a great lack of... junk. A lot of folks don't have a garage or an attic or a basement to store a bicycle. So, I suspect that if one isn't a regular bicycle rider, they might very well not have a bicycle laying about waiting for that once in seven years when the transit goes on strike.

I am willing to bet that in the USA, bicycles might very well outnumber humans. Unlike humans, bicycles never die, they just get buried alive.

I don't think this is the case in many European cities.