THIS IS FROM A FEW MONTHS AGO, BUT I HAD MISSED IT: The New York Subway System Is Beyond Repair.

The New York City subway is a miracle, especially at 3 a.m. on a Friday night. But the system is also falling apart, and it’s going to cost billions to keep the old trains running: $19 billion, at least according to one estimate from city planners. The time has come to give up on the 19th-century idea of public transportation, and leap for the autonomous future.

Right now, fully autonomous cars are rolling around Pittsburgh, the San Francisco Bay area, and parts of Michigan, shuttling people from here to there with minimal manual intervention. Instead of fixing the old trains, let’s rip out the tracks and fill the tunnels with fleets of autonomous vehicles running on pavement. The result would be radical improvements in throughput while saving money and increasing the ability of the system to survive a fire, flood, or terrorist attack.

These subterranean highways would be dramatically simpler than public roadways for an autonomous artificially intelligent system because the tunnels could be limited to authorized vehicles only. No jaywalkers on cellphones. No babies in runaway carriages. Just a collection of competing fleets, centrally orchestrated and offering different levels of service to different groups at different prices.

Yes, but would this offer sufficient opportunities for graft?