Toronto

Yes but the next step is for people formerly in cars to move to these alternate modes of transportation which have higher density, thus if you're really successful at it, at least initially, freeing up more space than you took. Under that possibility, we end up with more empty space on the now narrower street. Which induces demand.

Again, I'm saying that under these assumptions, the author's argument is valid. I'm not saying it's valid in all circumstances or that's it's actually useful, outside of what he used it for. He made it to show that even if we're very good at improving the quality of life of commuters we shouldn't expect to have F150s driving at 50kph through downtown. It's not an argument I'd use in any other setting as it can be misused very easily by people that don't want improved transit or bike infra.