[ghaff]

>However, commuter rail has recovered less than other modes, so if some of those people are now driving to their office instead, then they will be making traffic worse

There's probably some of that. At one point I took commuter rail after traffic seemed as bad as ever and it was pretty empty. But last time I took commuter rail in during December, it was back to standing room only again from about Waltham. (That said, I think the schedule is still reduced relative to pre-pandemic which both skews the perception of how many people are taking the train and makes the train a less attractive option.)

I'm honestly not sure though how to square the number of cars apparently on the road at rush hour with reduced office occupancy. Some of it is probably day sensitivity (more people commuting mid-week than Monday/Friday) given that occupancy--depending on how it's measured--than actual office vacancy which is high but at 18% not that high.