Earlier quoted context omitted.
> The alternative to a boost in ridership is a boost in car commutes. Or walking... Do you walk a quarter mile or do you ride the bus? If the bus is free the number of able bodied people using the bus for trivial distances could increase.
The metro is full because people commute to their workplace. I don't think a significant fraction lives within walking distance of their job.
Metro rail is sexy, but it's only one part of the transport mix.