The number 1 easiest way to convince carbrains to support non-car-centric transportation infrastructure (in my experience)
"Giving people more viable alternatives to driving means more people will choose not to drive, so there will be fewer cars on the road, reducing traffic for drivers."
Concise, easy to understand, and accurate. I have used it at least a dozen times and it is remarkable how well it works.
Also—
"A bus is about twice as long as a car so it only needs to have four to six passengers on board to be more efficient than two cars."
As a car guy myself (barely), I think it's crazy that people are against mass transit.
Trains, teams, and busses are better by every conceivable metric, if your departure and destination is within like 20km of city outskirts. That's almost all traffic. If govts and people invested as much into mass transit as they do into roads, it'd be a no brainer. So much faster, and safer, and more convenient.
Usable mass transit 20km from the city? Now that would be nice. But it is still science fiction for most people. Today you are lucky if you have working mass transit just inside the city limits.