Further Critique of the Automated Highway System and MegaRail Concepts


J. Richard Guadagno, InTransSys, Cimarron Technology, Ltd.

June 29, 2000

Immediately after I sent my recent reply on this subject, I chanced to view an educational television program on what is probably today’s ultimate expression of computerized control systems for aircraft: the one used for Boeing’s new 777 airliner. This control system costs multiple millions of dollars for each plane, and the development costs may have run into billions. This plane was originally designed to fly itself – just as "smart cars" are supposed to drive themselves. But during one of the final flight tests, the entire computer system unaccountably locked up during what was supposed to be a routine landing. As a result, the plane crashed, killing the pilots on board. After this incident, Boeing wisely decided to add a manual over-ride to the control system, and to require the presence of at least one skilled and experienced pilot in the cockpit for every flight. In most cases, these pilots will act merely as observers, but the finite chance of error even in a system as sophisticated as this one requires that a pilot must be present and alert at all times if adequate safety is to be achieved.

Airliners spend only a tiny fraction of their total travel time on the ground, during takeoffs, landings, and taxiing. And all of this time is spent in an area which is far better monitored and controlled than any highway or rail line. Once these planes are airborne, they fly through airspace which, by comparison, is almost completely free of obstacles. And it is known that each blip which does show up on radar is one of a very limited number of objects which are capable of flying through the air. Each of these must be avoided – and can very easily be avoided – simply by diverting the plane in any direction.

By further comparison, even the most carefully attended highway or surface rail line is rife with unexpected obstacles which are capable of disrupting traffic and causing accidents. Thus if the techniques developed for flight control are to be applied to surface ground travel, the latter control systems must be even more reliable – and in many ways far more sophisticated – than that for the 777; otherwise adequate safety cannot be assured. Visual or other kinds of observation must be developed to detect each of the many potential hazards I mentioned in my earlier missive: people or animals in the traffic lane; ice, snow, or water; rocks, sand, mud, or other natural weather or geological hazards; debris from other vehicles or from outside sources; disabled or dilatory vehicles – and thousands of other possibilities. Moreover, this detection system must also be able to tell whether that basketball-sized object lying in the road ahead is indeed a basketball, or a rock, or a dog, or a raccoon, or a suitcase, or a terrorist’s bomb, or a child’s balloon, or the child itself. For each of these items a different, properly designed, and previously anticipated evasive action must be programmed into the control computer.

Comparing the many working parts of a typical large airliner with the much smaller number for a car, these control systems may not cost multiple millions of dollars for each vehicle, but they will certainly cost multiple thousands. And for what gain? Simply to make it a bit easier for a motorist to drive during certain rush-hour periods, and to accomplish nothing more.

But can even this modest goal really be accomplished? Have devices already been built and tested which can truly accomplish all of the necessary actions outlined above? Have they even been designed yet? Have the problems demanding these steps even been acknowledged by the proponents of automated highways? If so, where are the data? If these things have not yet been done, how can anyone dare to make such claims as "The entire population, including the young, the old, and the infirm, might enjoy a higher level of mobility without requiring advanced driving skills."?

By contrast, most of these things can be accomplished quite easily through a properly designed elevated system. By locating the actual traffic corridors above all of the aforementioned hazards, all of them which are related to possible interference from other occupation (authorized or otherwise) of the roadway surface can be eliminated, and no all-seeing and all-prescient electronic detection systems are needed. Moreover, as Shladover recognizes, the problem of locating new automated traffic lanes along existing surface traffic corridors is a very difficult one, both technologically and politically. But this problem is also eliminated by elevated systems, which can be constructed above virtually any existing highway, road, or street right-of-way without interfering with what goes on below. It is time for us to acknowledge the fact that surface roadways are really suitable only for limited range, limited speed, limited capacity local traffic, and that they became obsolete for high speed, long distance, high capacity transportation a long time ago.

For illustration, let us compare the consummate complexity required to control the positions of a large number of vehicles traveling on an automated highway with that needed to accomplish the same goal on selected elevated rail systems. Let’s begin with the Integrated Transportation System (InTranSys), or any other which is powered by a linear synchronous motor. The only thing necessary to achieve absolute, split-second control of both the speeds and positions of hundreds of thousands of vehicles over very long periods of time is some means of producing reliable alternating current electricity. As anyone who has ever looked at an electric clock knows very well, such a means was developed many decades ago and is already in service throughout the world. Nothing remains to be designed or developed, and no tests are necessary to prove that such a system is capable of doing a far better job than a complex internet of multiple computers could ever hope to attain.

The only potential drawback to such a system is the occasional power loss incident, which today plagues various areas from time to time. But the causes of virtually all such power outages are either (1) the downing of power lines which are exposed to the weather and which may fail under conditions of extremely strong winds or severe icing, and (2) a system failure due to a severe power demand surge in one portion of the network grid. Recognizing these problems, InTranSys has been designed so that (1) all power lines throughout the entire system will be enclosed within the same sturdy reinforced concrete structures which support the system itself, and (2) the transportation system would produce all of its own power. No interchange with outside power grids would be allowed, with the exception of the possible sale of surplus power to adjacent grids – all at the discretion of InTranSys, of course.

Let’s also look at another proposed elevated rail system – MegaRail. It differs from InTranSys in three significant ways. First of all, its propulsion system would consist not of a linear synchronous motor, but of an unspecified type of "conventional" electric motor instead. Whatever form this motor takes, it would be of a variable speed type and would therefore require the use of separate speed and position control mechanisms for vehicles traveling on the system. At the present time, the promoters of MegaRail plan to use the same aircraft-derived control systems which the automated highway system proponents have chosen. While the dual problems of interference from surface-derived hazards and the incapacitation of vehicles due to flat tires, running out of gas, etc., of MegaRail would be eliminated, just as they would with InTranSys, the difficulty of spacing the vehicles along the track would still remain.

Thus the same complex and expensive control computer network, located both within the vehicle "ferries" and alongside the roadway (as well as at a central control station) would have to be used, with all of its shortcomings and uncertainties. By contrast, InTranSys, because of its use of linear synchronous motors, would need only a single centralized computer to control all traffic over a region approximately the size of a typical state (or, in the case of New England, six states). Moreover, this computer would be a far simpler device than those needed for either automated highways or MegaRail, since each vehicle’s journey would be described solely by the numbers of the origin and destination stations, plus a binary series of 0s and 1s to designate the direction of travel at each switch encountered along the way. No computers would be required by the vehicles traveling on InTranSys. However, since these vehicles would always be connected electrically with the system, telephone or any other electronic connections would always be readily available.

The second major difference between MegaRail and InTranSys is that the former plans to support its ferries (called "carriers" for InTranSys) on rubber tires running on flat metal surfaces instead of on steel wheels running on steel rails. Rubber tires running steadily at speeds of well over 100 miles per hour heat up rapidly from flexing and friction with the roadway. It cannot be stated until the tire design is known and the tires tested how long – or how far – such tires could be expected to operate. But race track experience indicates that their lifetimes would be quite limited, perhaps only a fraction of a typical cross-country trip. This introduces a danger similar to that of a vehicle on an automated highway having a flat tire – a danger which must be addressed for this system as well, with both its expected frequency of occurrence and the magnitude of its consequences being both analyzed and tested before any traffic can be allowed on the system.

The third difference between InTranSys and both MegaRail and automated highways is that the vehicles riding on InTranSys would always be connected to an electrical power source and (if desired) communication lines. This allows the use of both heating and air-conditioning systems (as well as other appliances) powered by electricity instead of by the vehicles’ engines. Not only would this method be many times more energy efficient, but it would also allow – together with the absolute control allowed by the use of linear synchronous motors – consecutive vehicles to be placed as close together as seven inches at a speed of 150 mph without any chance of colliding. Both automated highway and MegaRail advocates propose comparable minimum distances. But neither of them specifies how this is to be accomplished. The separate control systems which have been proposed are not capable of anything even close to this spacing.

And even if some device should someday be invented which would indeed allow such close spacing, they could not be used safely. In his article, Steven Shladover states that "Fuel consumption and polluting emissions might be reduced by smoothing traffic flow [that is, delaying the departure of some users] and running vehicles close enough together to benefit from aerodynamic drafting". But the cars’ engines on automated highways would be running throughout this entire period, and MegaRail proposes that they would also be running to supply heat or air-conditioning when needed. Either method would eject the toxic exhaust gases from one vehicle directly into the air intake of the succeeding one under such conditions. Such a "train" of cars might then arrive with living passengers remaining only in the lead vehicle! Only a system which is entirely electrically powered – and thus always free from any localized toxic exhaust – can safely be used in this way (InTranSys plans to lock out engine ignition during transit). For both MegaRail and automated highways, the spacing between consecutive vehicles must instead be maximized to a significant degree to prevent health damage. And this necessity would reduce the maximum traffic capacity of either system to only a tiny fraction of that of InTranSys.

Another very critical factor must also be considered when comparing these alternatives: energy efficiency. The use of rubber tires instead of steel wheels for MegaRail is likely to double its energy consumption relative to that for InTranSys, and the use of "conventional" electric motors instead of the super-efficient linear synchronous motors would bring about even greater energy losses. But this inefficiency pales in comparison with that of automated highways, which would continue to use the super-inefficient internal combustion engine for propulsion. This feature, together with others, would cause automated highways to require at least ten times as much energy to move a given vehicle from one place to another as would a system like InTranSys! Today’s growing awareness of the limited nature of the world’s petroleum and other natural chemical energy resources dictates that only the most efficient systems can really be considered if we are going to provide long-term sustainable transportation in the future. And this restriction certainly does not include automated highways.

Why does our government persist in throwing our tax money away on such projects, which not only pursue goals which are patently trivial, but are not even capable of effectively achieving those modest intentions? At the same time, why does it ignore alternatives which not only seek more noble accomplishments, but are able to actually reach them with far greater facility and at a far lower cost? Why are we so entranced with the status quo that we are willing to preserve an institution as archaic as the internal combustion engine, even when it means sacrificing the future of our society? What we need instead is a national transportation policy which really makes sense. We need a policy which realistically outlines our future goals, reviews the resources – both natural and technological – which are available to us, and then seeks the best way to use that technology and those resources to achieve those goals. Anything less is merely an exercise in futility.


Last modified: June 29, 2000