The existing rule, sadly, evaluates proposals almost exclusively on the basis of how much time a new rail line shaves off commutes. But taking a train station-to-station rather than driving a car door-to-door is guaranteed to be slower unless traffic jams are severe. This has biased new mass-transit construction in favor of a very particular kind of project: First identify a highway that’s already extremely congested and where widening it is either politically or logistically impossible. Then build commuter-rail tracks in the highway median. Put the stations far apart from one another so that trains can cruise at maximum speed for a long time. Surround the stations with parking lots. Driving your car to a park-and-ride station and taking the train downtown is now cheaper and perhaps faster than the average trip on the congested highway.