I toured the US with my bicycle for 5 months this year on a Walmart bikes. Each one lasted only 1 month (1000 miles) before it developed serious mechanical problems like broken spokes. But it was much more economical than an expensive touring bicycle: For example, every time I flew domestically, it was very expensive to take it as checked luggage. So I left it at the airport and bought a new one at the other side.

A bicycle (or a scooter) weighs a fraction of a car, so even if I replace it frequently, it uses much less raw materials per mile, especially if you include the fossil fuels consumed.

I never rode a bird, but I was sad when I saw the cops banning them from Venice beach in August. Hopefully the city will embrace the new technology and build enough (shared) infrastructure (bike lanes / sidewalks).