If I recall correctly, when everything ran on petrol and diesel, it was said that a single-occupancy car emitted 5x as much CO2 as riding a packed ("efficient")

If I recall correctly, when everything ran on petrol and diesel, it was said that a single-occupancy car emitted 5x as much CO2 as riding a packed ("efficient") train. That this ratio has dropped from 5x to 2x says to me that electric cars have gotten a lot more efficient (more aerodynamic designs, which helps increase range).