The problem is one of the value of time, thus this "resurgence" in mass transit is temporary.

Say it takes an average commuter 2 gallons of gas to get to work and back. At $4 a gallon that's $8 a day he spends only on gas.

Now say that same commuter opts for mass transit. Assume it is fully taxpayer subsidized e.g. no direct user fees, e.g. it's "free" to whoever shows up at the station. However, the time it takes to use mass transit results in an extra hour per day that is otherwise spent at leisure.

If the commuter values his time at $8 an hour or less, he'll continue to use the mass transit.

If the commuter values his time at over $8 an hour, he'll revert back to his private auto.

Personally, I value my leisure at well over $8 a hour. I believe most professional people do as well.