PRT is a confusing soup of construction, computing, vehicle manufacture, public works, system maintenance, and a bunch of other stuff. It is a complicated business model and it is difficult to estimate costs. What is worse, there is a tendency for would-be providers to estimate costs on a per mile/kilometer basis, which further confuses things. After all, vehicles, track, stations and control each have their own costs, lifecycles, and logic. Building vehicles, for example, has very little in common with building track or stations. The “per/mile” estimate is especially problematic in view of the landscape we face in the US. Here, our cities have grown into a suburban sprawl that has little consistency in terms of the placement of destination-rich areas.
To help the reader understand how this came to be, let me recount what was told to me, back in the seventies, about a little “up-and-coming” real estate developer, Trammel Crow. His formula for success, I was told, was really quite simple. First, find a growing city. Take the main road out of town until the land is sold by the acre, instead of by lot, and by some frontage. Build a tilt-slab office/warehouse on it, put it up for rent, and wait. It reminds me of playing Monopoly. Instead of using all of your money to buy Boardwalk, you can buy the cheaper Baltic Avenue, and “develop” it with houses instead. In either case, though, you buy and hold, while investing as much as you can afford to make it into an income producer in the meantime. This is instructive in understanding how cities develop such dysfunctional layouts. Land developers are, underneath it all, land holders, and often simply have something minimal on that land to pay the taxes and generate a little income while they wait for it to appreciate. This also helps to explain the vast parking lots that take up so much of our cities. Only at Christmas are they anywhere near filled. The land owners simply don’t have the money to build and maintain anything more ambitious. Even if they have the cash they are more likely to buy additional land and do the same thing elsewhere with those funds instead. Anyway, this has helped contribute to retail outlets that are big and far from the road, and getting from one such store to another is often not a walkable distance. This effect is also coupled with the effect of freeways, since freeway frontage offers an ideal place to exercise that Trammel Crow model, except the lease is to “big box” retailers, who have discovered that economies of scale are more easily exercised away from the expensive downtown areas.
When it comes to walkable, integrated urban/suburban environments, it is usually the old parts of town that shine. Little towns that get absorbed by cities usually retain their main streets and hopefully a bit of their charm. But these, too, are “destination islands” in a sea of sprawl.
For a PRT system to be a viable way to get around, it has to go to these important destinations. If they are in clusters separated by substantial distances then this strongly suggests a PRT design that allows more than a single speed. It suggests a design that is similar to how freeways work, where there is a slower feeder that runs parallel to the faster main highway. This is because the deceleration and turning are disruptive to the faster, distance-oriented thru-traffic. In the case of PRT serving disparate, clustered destinations, it is possible that the best design might be for the local, feeder system to be quite slow. This would allow an absolute minimum of the double track required for off-line stations and allow for extremely tight turns. Faster track would connect these destination clusters.
This ties in with the discussion of land development and PRT cost estimation in the following way: First, it is important to get some kind of handle on the costs of running track alone. The downtown PRT models tend to assume blanket coverage for a pedestrian rich area. In the case of destination-rich freeway frontage, the proportion of stations and vehicles per track distance would seem similar, being based on walkable distances, although it would be linear, rather than based on loops covering city blocks. The “old town” destinations, referenced above, are classic downtown loops, just scaled back to one or two. But connecting all of these (and the actual central business district) is fast track. So when figures like ten to twenty million dollars per mile get tossed around, it is highly misleading. I would guess this stationless track, on public easements, would be more like 2-3 million per mile. This fast track could easily pay for itself, it would seem, by virtue of the fact that it would cut through so much traffic.
Those “big-box” destinations tend to have that extra parking lot space, and this would seem to be a great place to put PRT stations. But the land is rarely owned by the retailer, and therefore it makes little difference if that retailer wants to provide PRT access or not. The land owner has his own agenda, and understanding his wants and needs is what counts.
The first thing to consider is that he won’t want to give up sovereignty over a single square inch. That means anything permanent is problematic. At present, the advantage of hosting a PRT station is only theoretical and it cannot be expected that this is all a landholder would want at this time. This is especially true if there are excessive requirements for utilities, permits, digging and the like. On the other hand, the land in question is often of very little immediate value to the landowner, since building anything large on it would block their main tenants’ visibility from the street. So it comes down to that ultimate grease to getting things done – profit. How can the land owner directly make money by having a station? It is pretty obvious that in an ideal world, the pedestrian traffic generated by the station would be coveted by the tenants to the point that they would pay greater amounts to lease their stores. The landowner would therefore willingly give up the rights to enough space for a station. Let’s keep our optimism in check, at least for now, and say we have to sweeten the deal.
In theory he could get a small piece of every transaction, and there is also the potential for parking revenue. The amount charged couldn’t be much, because otherwise people would park for free in the guise of being store customers, a potential problem with almost any good transit system that is close to retail outlets. But if the parking is right next to the station, and the station is easily removable, and there is nothing for the landowner to do but collect money, I think there is potential. Electronic payment means can integrate parking fees and PRT fares into a single transaction.
What is good, though, is that this helps solve a major problem of transitioning from a car-based to a pedestrian based cityscape. Absent a real “last mile solution,” PRT could still make a huge contribution to traffic reduction. If the system doesn’t get to your door, it should at least get to your grocery store.
This all begs a bunch of questions that need to be addressed in a future post. Specifically, we need to examine further the issue of decoupling the stations from the track, from the vehicles, from the control. Each has its own rate initial costs, rates of depreciation, etc. Varying the ratios between them greatly influence the profitability of any venture. Can a bunch small stations be used in place of a bigger one? If we are going to bridge a bunch of destination clusters, how far apart is too far? Can the business models for each be separated and therefore simplified to be made more attractive to investors? We’ll get back to this. Stay tuned!
