Well you can already do that. I have 3 vehicles. A 2021 Radrunner RadPower 2 E-bike, a 2018 Chevy Bolt EV, and a 2008 Dodge Sprinter. I've converted the Sprinter to run on used cooking oil. I listed them in that order, as that is the most to least used. I basically never use my EV or Sprinter by myself. I might be in the sprinter alone until I get to whatever friend I am helping move big stuff, but then I have at least one other person in the van.
I realize that doesn't do anything for anyone else, but it eliminates the vast majority of my carbon footprint since the sun is powering the first two vehicles, and my house.