Here’s some good news for people who want more rapid transit service in US cities, and soon.

In the US, all passenger rail services that could potentially mix with freight are governed by the regulations of the Federal Railroad Administration (FRA). This applies not just to Amtrak but also, critically, to “commuter” rail lines, crucial rail transit services that run on freight railways.

If cities wanted to rapidly upgrade their rail transit systems, the cheapest way is often using upgraded commuter rail rather than building new lines. Many major cities have large networks of radial commuter rail lines [typically originally freight lines] which, if upgraded to run every 15 minutes or better all day, would effectively become metro lines, on the cheap. You’ll find this level of service in many major metro areas overseas. Toronto’s Smart Track plan is exactly this idea.

The problem, as always, is frequency, which in turn is a problem of operating cost. Most US commuter rail systems are far too infrequent to be useful for anything but 9-5 commuting, even though many of them run through dense urban fabric where the demand is there for all-day frequent service.

The Obama FRA, responding to several freight rail disasters, had proposed a rule mandating two-person crews, and had quietly inserted language extending this to passenger rail, even though passenger and freight rail present very different safety issues. Those requirements would have made commuter rail service too expensive to run frequently enough for it to be useful, and would have persisted regardless of whether technological developments improved the safety outcomes of one-person crews.

The Federal Railroad Administration has just announced that it will stop requiring two-person crews and preempt state requirements to do so. If this were a genuine safety issues, I’d be alarmed, but it really isn’t. The new FRA position liberates transit agencies and other local governments to negotiate the right solution with their unions in the context of what’s technologically possible.

Yes, removing this requirement is a “conservative” idea that would be unlikely to come from a Democratic administration. But it removes a significant barrier to providing more useful urban public transit, which leads to all kinds of benefits for equity, prosperity, and the environment.