In 2021, transportation accounted for 28% of U.S. CO2 emissions, the largest source by economic sector. Absolutely, we need to address cars to reduce emissions; they're not getting that much better. Getting rid of them won't fix the problem, but conversely, fixing the problem requires getting rid of most of them. But why does it have to be rails? What if it was a café near your house? A doctor's practice? A bookstore? It's not foreordained that everything has to be so far apart that you need motorized transport (car or train) to get to it. The large majority of car trips Americans take are short distances, not cross-country journeys for which we need high-speed rail or airliners. Do away with single-use zoning, put the places people go every day close to where they live, and we eliminate the need for a huge number of daily car trips. No rails through your front yard needed.