Self-Driving Transit

Any technology which allows for self-driving cars will allow for self-driving shuttles, buses, and trains. Rumors of transit’s death have been greatly exaggerated.

The main impact of labor costs on route and vehicle choice is to bias operators towards larger vehicles. Infrequent “circulator” buses are less convenient than taxi shuttles, but it’s cheaper to pay a single operator to drive a mostly-empty bus around in a big loop than it is to pay multiple cab drivers to be on call, even if the latter system might pick up a few extra riders.

Likewise, spending a lot of money for a rail system makes sense if each train can replace several buses. Whatever the merits of Houston’s LRT extensions, the original 2004 Main Street Line made sense as a replacement for the numerous buses operating between TMC and Downtown.

But self-driving transit changes this calculus. Remove the operator from the equation a 2x or 3x multiple for LRT vs bus costs becomes a 4x or 5x multiple. There is no way to justify the cost of a guideway.

(Do not respond with “but Ottawa”, or similarly played-out arguments. Jarrett Walker will spend the rest of his career batting down bad anti-bus arguments, and I see no reason to duplicate those efforts).

Across the board, self-driving technology will shift the cost curve in favor of smaller, less-expensive transit vehicles. What it won’t do is promote personal auto usage. The labor cost of the personal automobile is already zero; the driver volunteers to drive himself. And adding self-driving technology won’t make cars any cheaper*.

Rail won’t completely die, either. Very high speeds – 100, 125, or 220mph – require steel wheel on steel rail, or an alternate technology that offers even less rolling resistance (e.g. maglev). Express rail offers a ride that is orders of magnitude nicer than buses, even on dedicated guideways. And the visual presence of trains acts as a sort of civic virtue signal.

Instead of talking about transit’s impending death, we should instead be talking about more busways, and possibly building currently-planned rail lines as busways. These can be bus-only affairs like Pittsburgh, or they can be interconnected networks of managed lanes like what Houston *ought* to be building.

One thought on “Self-Driving Transit”

  1. I’m a proponent of the vision that privately-owned fleets of driverless jitneys (with lower labor costs, lower repair and maintenance costs, fewer casualty losses and lower insurance costs, and higher capital utilization rates) will be the end of transit as we know it. All fixed-route bus services and light rail systems (averaging about 17mph with a top speed of about 66mph) will vanish from our roadways; however, those guideways may become very valuable if operated as at-grade HOV lanes.

    More such lanes would be needed though, and by and large that’s where toll road authorities will come in.

    Yes, fast transit becomes more viable, but only over long distances with relatively few stops and in particular from the furthest edges of mature suburbs; its top speed is only one variable, but that benefit must be netted of acceleration and deceleration, wait times for transfers, indirect routing, and varying fixed costs associated with the boarding of any given vehicle by any given passenger. Those costs are probably very very low for high-capacity rapid transit during peak hours, but high for door-to-door jitneys. Off-peak hours may invert that paradigm. All the same, if getting to your final location requires the use of a jitney to get to transit and a jitney to get from transit to your final destination, that could skew things in favor of a single long-distance jitney that circulates door-to-door at either end of its route. That’s especially true over the course of a 24-hour day, and considering the impetus toward capital utilization.

    What that means is that the best possible way to implement mass transit is in a system that moves people from outside of a transit authority’s jurisdiction into it and vice versa. That is the same paradigm that exists for P&R, but it means that the furthest and most effective P&R lots are at the edge of the service area. This is inefficient and won’t be especially competitive with jitney services that know no such bounds. Thus, it is likely that for any kind of transit to be effective, there must be legislative reforms that start in the State legislature. Like it or not, in Texas you can bet money that these will favor suburban and rural areas. It wouldn’t surprise me if these are the levers that are used to justify TCR’s high-speed inter-city rail project(s) — with commuter rail spurs. As such systems would be a natural monopoly, it also wouldn’t surprise me if they were regulated and/or directly subsidized.

    One of the other things that’s likely to happen is that the private sector will re-envision transit centers. This will happen because peak-period congestion will be monetized. Consumers tend to under-value their time when it is spent in traffic, so when presented with additional out-of-pocket costs associated with peak-period commutes, it is likely that they will defer those commutes in order to save money. Especially in the late afternoon and early evening hours, after work, during happy hour…if you get my drift. As it happens, drinking is a complementary good with impulse purchases. I would expect that this is what the next generation of transit centers will look like. Rush hours will become elongated, but be less congested. Actually, I would expect that congestion even during peak hours would decrease.

    If coverage is addressed by this new technology and congestion is also addressed, and the private sector addresses jitney fleets, toll roads, and inter-city fast transit…what’s left for the transit agency? The answer is subsidy, I think. There will be special populations, especially those that are elderly or disabled, that probably can’t be served very well without subsidy. It may also be that entities which are inherently monopolistic in nature require some regulation and occasionally some enticement in order to build certain ramps and thoroughfares. This is not ideal, but on net it might be desirable. I think that that’s about the extent of it.

    This is a complex issue though, and my prognostications are intuitive. I welcome any criticism you may have. Really, I do. Bring it on. Please. I enjoy this.

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