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."
The buses around here are 40 feet long. A Toyota Camry is 16 feet long; a Chevrolet Silverado 1500 is just over 19 feet long. Add in 4 feet of buffer distance when stopped, and the bus is longer than 2 Camrys, but shorter than 2 Silverados. Take the average of cars on the road, and it's legit to say that a bus is about twice as long as a car.