All forms of commuting do not pay their way
If walking costs you a dollar then society pays $0.01.
If biking costs you a dollar then society pays $0.08.
If bussing costs you a dollar then society pays $1.50.
If driving costs you a dollar then society pays $9.20.
Ref: https://twitter.com/MobilityLabTeam/status/679336712586305536?s=09