One, they are much better on gas use. So less energy in general to move them.
Two, they are much lighter, which as we are discovering with electric vehicles, matters a great deal in how horrible the tire wear is (and remember that 28% of microplastics in the environment come from car tire degradation alone!).
Three, for traffic purposes, they are much, much better. They are smaller, so recall that picture that floats around of how much space 100 passengers takes up. They aren’t near the train/bus level, but are closer to the bicycle portion of the picture than the cars. It becomes even better if they are scooters compared to motorcycles (scooters are generally even lighter and have smaller engines with better gas usage). I always hear the stat thrown around that if 25% of individuals switched to motorcycles, modern traffic jams in cities (in America, I guess, where I hear it uttered) would nearly disappear.
They pollute more and use more energy to move a single person.
Motorcycles are worse than cars…
How exactly does a motorcycle that gets 60 mpg (3.92 l/100 km) take more energy to move a single person that a car that gets 25 mpg (9.4 l/100 km)? Notice that almost nobody carpools in America, which is the subject of this post.
Also note that almost all motorcycles sold worldwide comply with Euro 5 emissions standards.
Emissions systems. Do you realize just how toxic something without a catalytic converter is? Let alone one that doesn’t work for shit like the types installed on bikes.
Also a car is probably FAR more efficient at burning fuel than a bike. The efficient burn lets out even less toxic gasses despite using 3x the fuel.
Take the totally emissions free lawn mower market and scale down emissions a bit since bikes do have some emissions equipment and electronic fuel injection. But they really don’t have much, and they’re very often just removed/bypassed.
https://psci.princeton.edu/tips/2020/5/11/law-maintenance-and-climate-change