I shouldn't have included maintained in there because I just meant the emissions for manufacture. The emissions for building an electric car is more than that of a combustion engine car, and building a mile of single lane road dwarfs both of those. So switching to electric cars keeps us building roads and increases emissions at the time manufacture. To get the real story, one needs to consider the use of and maintenance of these things. At some point, there is a crossover point where electric cars have less total emissions than combustion cars. But the use of electric cars will not slow the building, use, and maintenance. If anything, they will increase it because they make buying and owning a car sexy again. Plus, electric cars are far heavier than combustion cars, which will increase road wear. And most analyses don't include battery recycling and disposal as part of an electric cars emissions. So electric cars are probably or even maybe a win in the long term, but the simple act of having electric cars isn't enough.

My point is that one can't simply look at the power production of a car as the sole comparison, and I think that also holds true for power plants. I just haven't seen this analysis for fusion plants. They will be a good thing for sure, but I worry many think it's a silver bullet, and I'd like to understand their affects once they're on the scene.

Why do you keep talking about building a mile of road? There are many more cars in the US than there are miles of road, and the replacement time of roads is at least decades.