Consider someone who for either family or affordability reasons is unable to live in San Francisco, where they make their living.
Their daily commute is long. The cost of the commute is nontrivial, relative to the net salary.
Does the IRS offer any kind of reprieve? Are transportation or lodging costs deductible in any way?
In case your thinking goes "Why should that be the case? They are making the choice to live far", it's worthwhile to mention here, ever so briefly, that such an incentive to commute would in the long run ammeliorate transportation networks (for example, trains run more often, paid by ticket revenue), which would encourage more people to avoid driving (even if the car is self-driven). And then those who continue to drive also will be happier, because they'll be able to breeze on the highways.