Monday, August 10, 2015
In our last exciting episode I promised to explore cooperative robotics, but there is an unavoidable side issue that is worth at least one post in itself, one that high-jacks the whole subject. What I am referring to is self-driving cars. It is not just that PRT and automobile automation have such obvious similarities that makes the subject a prerequisite to discussing PRT control. It is also the fact that self-driving cars may actually change the definition and purpose of PRT.
Self-driving cars are not just about following directions and staying on the road. Spinoff features such as automatic braking for collision avoidance are already widely available in everyday production models. Since self-driving features often involve technologies that clearly can enhance safety, there is an “arms race” in this regard. With communication between vehicles (“I’m slamming on the brakes, so you better, too!”) and awareness of real-time traffic, (such as could be monitored, compiled and reported by the vehicles themselves) it is not hard to see how cars could be made to operate within a sort of “hive mind,” to the benefit of the group. This is basically a PRT operating system and is a wakeup call to self-steering PRT systems like ULTra or ToGethere, whose technologies are getting leapfrogged by this trend. Notably, the self-driving paradigm is proving that a high degree of autonomous control is doable, challenging the centralized control schemes of only a few years back.
Does self-driving auto technology render PRT irrelevant? Do self-driving cars eliminate the same problems that PRT was to solve?
The short answer is no. The question does, however, illustrate how various flavors of PRT have very different challenges in this new technological landscape. What, for example, should the business model be for ULTra in a world transitioning to self-driving taxis that may not need guideways or stations? Of course that may be quite a ways off, and maybe it is Google who should be approaching ULTra. After all, every cent ULTra has made is a cent more than Google has made on its robocars, with Google putting all of their eggs in a business-model-basket that is still a bit of a head-scratcher and is contingent on many unanswered questions when it comes to safety.
So far Google and the others have seemingly only taken their vehicles out in decent conditions, weather-wise, content to garner impressive numbers of miles without incident. But how do they handle being behind a vehicle that is dropping debris? Or on patchy “black ice?” Fresh snow or street flooding can completely obscure where the road is. Timid response, in these instances, that would prevent lawsuits is also the kind of driving that would snarl traffic. Imagine a car that is afraid to go through ankle-deep water and so just stops! Can a robocar understand when weather conditions are deteriorating too much to enter the freeway or understand the significance of a funnel cloud? Humans usually know when they should stay put or go back. Will Google be able to give that much common sense to their cars? What about morality? Will they know to hit the truck to avoid the woman with the baby carriage?
It has been reported that, at least some states, they cannot dispense with manual controls (such as a steering wheel) nor the human seated so as to operate them. This leads one to wonder under what conditions the authorities would permit such use. Beyond that, what is the profit model that trumps the obvious, added liability issues? Do drivers really want to relinquish all control and do manufacturers really want to sell mechanically stripped down cars with no sex appeal?
A safe starting point would be a special lane or only going at fairly slow speeds. (i.e. a mode similar to current pavement-running PRT systems) After all, many localities allow golf cart type vehicles on public roads, and these need no horns, airbags, seat belts, etc., as they don’t go that fast. While this would probably be allowable, it does little to solve urban congestion and so, by itself, risks irrelevancy.
Interestingly, there are flavors of PRT that have just the opposite problem. SkyTran, for example, is really built more for speed than for serving little stations in every nook and cranny of a typical city. Suspended systems, in general, have the potential to move people from one side of town to the other quite quickly using an inexpensive, minimalistic track, but like all PRT, suffer from the potential problem of not having a sufficient number stations and walk-up customers to create the cash flow to pay-down the system components and still provide a return on investment. It’s the old first and last mile problem. Could self-driving automobiles be the answer to aggregating more PRT passengers at fewer stations? Quite possibly.
Uber has expressed interest in self-driving cars, and car sharing schemes like Zip Car raise interesting questions about ownership. Why garage a vehicle that could be gainfully employed elsewhere while you are not using it? Why own a vehicle at all – especially if there is one parked close by that will come to you when summoned?
Once upon a time, PRT offered a unique combination of benefits that could not be had otherwise. It was automated, elevated, personal, fast, but it was only practical within an interdependent framework of technologies. Over time, developments in sensor, communications and computing gave advantage to a variety of methodologies enabling new designs that emphasized varying missions and business models. The emergence of autonomous cars, it seems, puts a focus on one of the original themes, which is a network of fast, elevated, non-stop corridors that are unencumbered by the gridlock below. This mission is unthreatened by the self-driving car revolution and, indeed, may well benefit from it. PRT, at this point, needs to be considered not as a fleet of automated taxis, but as a network of personally navigable urban wormholes. The automated taxi aspect is now only a means to an end, not the end itself.
Originally the idea was to space PRT stations so that each was reasonably within reach by walking. Now perhaps each station could garage a half-dozen automated taxis, giving such stations much broader reach. This associated service would not have to extend very far to cut the number of stations to a fraction of what would otherwise be required. This scheme works perfectly with car sharing, carpooling, or even private ownership. Even if each fully self-driving “car” can only go a few blocks, with similar vehicles and capabilities at each end of the PRT “wormhole,” the combination could be very synergistic. The timing and payments between the two systems could be integrated, even if under different ownership. On such limited routes where the speed limits are low there is much less reason to require a driver, meaning self-driving cars are clearly ready for this NOW. Where special lanes could be created, ULTra is also ready to go as well.
Side note: The above combination offers less advantage for the SMART PRT designs shown within this blog because SMART is specifically designed to address the “last mile” problem with vertical capabilities and stationless pickup and drop-off capabilities. Of course any infrastructure, surface or elevated, will undoubtedly face obstacles on certain routes, and so alternatives are always welcome. That being said…
It is important to note that slow, short-haul, self-driving “taxis” also offer synergy with other forms of mass transit, such as light rail, subways, scheduled shuttles and so forth. Even with limited routes, (There might be too much traffic on public roads and no room for a special lane) phone apps could be used to locate the nearest suitable pickup point. Such pickup points could enhance the value of properties that are otherwise inconveniently remote from mass transit. Short hauls to such existing transit hubs seems like a good business model for such a product/service right now and deployment of such FULLY robotic vehicles, even at slow speeds, might serve similar R&D aims as the current, unpaid efforts and would offer a potential opportunity to cement a leadership position in the field while generating revenue.
Self-driving cars, capable of full city and highway use without special lanes or a standby driver are still a long ways off for general use, and the eventual payoff for the producers of such vehicles is questionable. Short range, slower vehicles face no particular obstacle to immediate adoption, however, and everybody from ULTra to Google to Uber to Zip and the various auto makers should jump on this opportunity to become leaders in this transitional space. Meanwhile PRT wannabes need to take note that the current technological backdrop no longer supports slower, station-intensive, short range systems. Instead, PRT companies should concentrate on designs that foster the cheapest, fastest network of elevated track possible, filling that one niche that automation itself cannot address.
Elevation has always been the answer to surface traffic congestion, but has always been prohibitively expensive (not to mention ugly and in-the-way) when scaled for heavy vehicles, and so gridlock continues. Like fiber-optics compared to copper, some form of light, affordable, high-speed “pipes” for moving people are inevitable, and the first barrier, autonomous yet cooperative automation, is falling away fast. Like that fiber-optic cable, the second barrier is what happens at each end – how data is efficiently transmitted and received. Hopefully self-driving vehicles will help provide comparable, easy-to-implement solutions for either end of the mobility solution that cities need so badly - that Urban Wormhole technology called PRT.