Compare transit and car commute costs.
Comparing a transit pass with driving fails if you count only fuel, which is typically less than half the true marginal cost of a commute mile. Adding a per-mile allowance for tyres, servicing and mileage depreciation — 22 cents is a reasonable middle figure — roughly doubles it. Parking is the third term and often the largest where it is charged daily. On these defaults driving costs about 320 dollars a month against 95 for the pass. Note this is a marginal comparison: it assumes you keep the car either way. If taking transit lets you go car-free, insurance and depreciation come out too and the saving multiplies.
Transit vs Car Cost
Monthly miles = one-way x 2 x commute days; driving = miles/mpg x fuel price + miles x wear rate + days x parking; saving = driving - transit pass
For a commute of any length into a place with paid parking, almost always. The gap narrows sharply if parking is free and the commute is short.
15 cents for an older paid-off car, 25-30 for a newer one where mileage drives depreciation. Government mileage reimbursement rates give a useful upper bound.