The Monorail in Mass Transit
will we ever see them?

watched "I, Robot" last week and was inspired by a few computer graphic representations of monorail trains passing futuristic cars on the way to the big city. They sure looked impressive ... but ... I had to wonder "Where are they going, specifically?" and "Where are they coming from, specifically?" and "Who the hell is riding them and for what reason when all those hyper-efficient cars are available on the roadway right beneath them?".

This is the problem that plagues the monorail. It looks and sounds great but on examination there are some really fundamental problems involved in their use. Chief among them is getting people to leave their cars for a mass transit system. So, the first thing to be examined is ...

"Why do people prefer their own cars"?

It's all too simple. Your car is a chauffeured limousine that waits slavishly on your demand to travel. The only hitch is that you are the limo driver. You go just when you are ready and ... barring mechanical problems ... you go just at the right time. No possible mode of transportation can beat the convenience of driving your own vehicle.

The drawbacks are:

  • Cost of ownership
  • Cost of gas, depreciation, maintenance and insurance
  • Excessive traffic delays
  • Parking
  • Danger (I've seen far too many cars overturned, several dead bodies on the road as well as the ubiquitous flower-supporting cross ("X" marks the spot where a loved one died).

Now, if you are going to own a car anyway, you can scratch out cost of ownership as irrelevant. And, if you take your car to work maybe parking is not a hassle. And, no one considers the danger of driving ... because ... bad things only happen to "someone else".

That leaves us with rush hour and the daily costs of driving as the only incentives for getting out of one's car ... just two things to use as an effective social crowbar. To get people into mass transit they must save significant time and money.

The Bus

The bus is reasonably cheap but few will give up their cars for a local bus. These things stop at every corner, are ugly, uncomfortable ... in short ... public ... and worse they generally don't run straight to where you want to go. Staying in your car saves you all that and you can listen to the radio, smoke and go the route you want ... they're private. So, a monorail that behaves like a bus (stopping locally) is absolutely out for serious mass transit. Buses have their place ... but it's an inherently limited place.

If a monorail can't stop locally you must get to where it stops by your own vehicle. So, we are looking for something that takes a percentage off your driving each day. You ride to the "station" get on the thing and go "where?". It can't go directly to your destination because that means local and local is out. Who would give up their car at the station only to be made to stop at everyone else's destination as well. "Local" is a serious time waster. Might as well be stuck in traffic on the freeway as stuck in mass transit that stops everywhere you don't want to be.

The Train

I've seen movies with a monorail going out in the country seemingly running overland ... a hundred mile ride. Is this really possible?

Short answer: NO

The reason that such a system will never be built is that if such were wanted a standard train would be built instead. Out in the country, the small "footprint" of a monorail is no longer of great importance. The somewhat larger footprint of a train track will do as well. It's simply a matter of "right of way". Once that is established, the regular train provides the added dimension of being able to carry heavy freight as well as passengers. I think anyone can see that building a monorail sufficiently robust to carry thousands of tons of coal would be prohibitively expensive. Better to just sit down on those two cheap steel rails on the ground and run a passenger train now and then.

A monorail in the country will never be made unless it is a specialty job like a nature trail through the Okefenoke Swamp. Don't ever expect to see one longer than 10-20 miles. After that ... build a simpler train.

Viable mass transit can only "relieve" the Rush Hour

If our monorail system is to work at all it must perform the function of, say, two added traffic lanes. Two at morning rush and two at afternoon rush hour. Figure the immense cost of adding a couple of lanes to a freeway (where there is no room for more) and that's what you have to work with as a construction cost.

Then you need to get a significant percentage of the drivers on that freeway to use it in order to relieve the congestion thereby making rush hour flow more freely thereby justifying the construction.

In order to stay non-local and yet deliver people straight to their jobs, it is necessary to serve only a select number of places. The places where lots of people go ... the most common destinations. Here where I live in the Dallas-Fort Worth area, a mass transit system that went to DFW Airport would significantly decrease traffic on the freeways adjacent and leading to it. If 40% of those drivers could be crowbarred out of their cars and into mass transit, it would be like building another freeway on top of the present structure ... a double decker.

Some rider numbers

If you are in a typical stop & go driving situation, there is maybe one car per 40 feet per lane. That's about 132 cars per mile. And ... about 400 per mile in a three lane freeway. Rush hour lasts about three hours and the velocity of the cars averages maybe 30 mph ... so ... that's about 35,000 people we're dealing with. Ballpark figures and I'm considering one person per car because car pools don't work either.

So, to make a big dent in this mess, we need to cajole about 15,000 souls out of their cars and onto our soon-to-be-designed monorail system. And that's just on one section of freeway (the section of freeway we're going to serve). Multiply that by whatever depending on your city ... but wherever you are, if you have a significant rush hour problem, you need to get some tens of thousands of cars off the road to make a major dent in that problem.


There is a web site devoted to   Monorails. Costs are discussed in the range of 6 million dollars per mile (el cheapo) to 65 million dollars per mile (el magnifico). I'm only interested in cheap stuff so I'll cut out a design hopefully in the 5 mil range ;o)

The cost to ride the system must be ... absolutely must be ... nothing at all. Not a penny is to be traded for a ride. Of course, taxes will pay for it but there won't be a tax for more freeways or widening them, etc. So, everyone who still uses the present freeway structure benefits as well. He will drive an open road at rush hour ... and a safer one at that.


This is the part of writing that I enjoy the most ... designing things I know can work (at least physically). Of course, it will never be built and rush hour will never go away in our lifetimes ... but ... it could (at least in principle). I'm designing my system for normal people who take their car to work every day by themselves and work at the airport. That's all. I don't work there myself but I see what's going on every day in that direction. And though I wouldn't use this system myself for that reason, it would get all those effin' cars out of my freakin' way so I could go where I want to in peace ;o)

My "line" will run in a loop travelling from about 15 miles south of the airport ... to the airport ... west about 15 miles ... then, arcing back to the start in sort of a quarter of a pie configuration. That's maybe fifty miles long. All monorails must go in a circle because you are going so send multiple "trains" down the same track in the same direction, one after the other, till all of my 15,000 riders are accomodated.

If there are say, 100 riders per train, I'll need 150 trains per rush hour to take them to the airport over the span of three hours. That comes out to nearly one full train per minute (if they were all coming out of one station ... which they won't be). To get people out quickly, we need to look to ...

Six Flags amusement park rides

Amusement park rides don't put out one train per minute because they make you where a seat belt and check everything before the ride pulls out. On my line nobody checks for you. You're on your own. But you're not going to fall out. There are no vertical loops or 45 degree slopes or sharp turns to scare anyone.

mono1.gif - 5kb However, park rides do have something to show in the area of loading-unloading. Their technique is usually a line for each entrance to the car. There is nothing ambiguous about whose turn to go is next. They also have a safety gate which opens when the next train is ready to load. We can dispense with that however in favor of a "Do not cross the yellow line till train stops". We are going to keep the loading platform but use both sides of the train to load.

We will leave one off-loading lane for those exiting the train. A one-way turnstile will keep people from entering there.

A Private Seat

In this system, two people never sit right next to each other. There is one person on each side of the rain but each individual is isolated from every other so that it resembles the situation in one's personal vehicle. You can see the other people but you're not touching them or so close as to feel compelled to converse with them. Most people go to work alone. No one wants to sit butt to butt with a stranger. Each seat has its own door which is just about the same as a car door except that the window will not roll down and an automatic electric lock will engage when the train is in motion.

When you get out, you are expected to close the door behind you if no one else it there to get on. The doors will not close automatically. They are simple car doors.

Don't forget ... there is "no charge". I should repeat this several times in this piece because it is very important. The rider doesn't pay his way ... taxes do. Everybody benefits because these people are not driving their cars. If any attempt is made to charge the rider ... they will abandon the system in large percentages ... and that's the end of mass transit right there ... nickeled and dimed to death.

monoseat.gif - 7kb

This is a comfortable seat made from hard molded plastic with no padding ... something like the stuff that one-piece molded plastic showers are made from. It's hard but it's comfortable for a 15-20 minute ride ... not so comfortable for a one hour ride. Get it? Cheap and durable. There are a couple of holes in the low part of the seat so that spilled coffee can fall to the floor and a small hole in the low point of the floor so that liquids will drain out there. To clean the car you just basically "hose it down" and let it air dry ... cheap.

Each seat must accommodate (comfortably) someone in the 400 pound range at 6'5". If you cannot accommodate this large person, he will take his big, heavy duty pick-up truck onto the freeway and run up your bumper. You could possibly put two smaller people in one seat ... if ... they are sexually intimate ... or ... are small kids.

monoint.gif - 5kb On the inside wall of the passenger compartment is a keypad for the rider to select his destination. You can push only one button so if you change your mind, you just press another button and that's your specified departure point. Why do this? Because this information can be used by the driver or a computer for routing purposes when combined with information about the numbers of people waiting at other stations. There are a finite number of seats ... and ... if a train is 97% full should it make an extra stop at a station where many people are waiting just to pick up three of them or continue on and let a following train stop there instead?

The door windows won't open (people wouldn't close them when exiting). So the car is HVAC'ed. The individual can select heat-vent-AC and direct the blower or turn it off entirely. There is also a reading light somewhere and that's about all the amenities there can be. And ... the driver can if necessary speak to the passengers individually or in any combination ... and ... hear what is going on in the cars to monitor disturbances, etc. Most likely, a computer would play the loudest sounds coming from the passengers and not the rest so that at any given time, the driver could hear someone shouting "Help" but not someone listening to a personal radio.

On the outside of each compartment is a light ... "red" for unavailable at this stop ... "green" available at this stop. Now, if you don't push a destination button, the driver or computer will think that your seat is not taken and show a green light. So when the train stops at a station that you don't intend to get off at, someone may open your door to get in and there will be a mean face looking at you when he finds that you've screwed up his ride expectations. Thus, when the train rolls into a station, the people standing on the line waiting can see plainly if they are getting on or not.


The doors are similar to car doors which everyone is familiar with. However, unlike car doors, these will close automatically when you let go of them. They are "gravity doors" ... meaning that when you open the door, you are also lifting the door on a screw hinge. The downward force of gravity then causes the door to close but not too fast and it clicks a door-handle operated latch which prevents it from bouncing open again. When the train is put in motion by the driver, a dead bolt automatically (electrically activated) locks the door and presses it more tightly to seal the door against air currents and noise.

It is important that the door close itself because if a person gets off and does not close the door and no one else is entering, it is unlikely that the door will be shut. This will happen often and the driver cannot get out to close doors at every stop ... and ... any other mechanism would be much more costly and less dependable.

What my train looks like

monosect.gif - 5kb Here is a cross-section of the passenger compartment. It's not much roomier than a car ... compact but not stuffy. It is supposed to weigh very little per passenger. In your car you take about ten to twentyfive times your weight to work with you. Here I'm looking for something closer to 3-5 times your weight and that includes the electric engine. Light and cheap.

I'm keeping the center of gravity about the mid-point on the rail so that in a turn there is no torque on the rail itself ... just a sideways push in the center. I regard this as the most stable design and therefore ... the cheapest as well because it requires the least amount of material.

The brake plates are for stopping the cars at the station by the station managers (not the driver). You pull back a lever and another plate lifts the weight of the car onto the brake plate and it slides metal on metal to stop the car. It's more of a cheap, emergency thing. The driver is the primary stopper with electrically activated brakes.

From the side, there is an engine which contains the electric motors for propelling the cars and a driver. I want 100 passengers so there would be 10 cars instead of 3.

monoside.gif - 3kb

There is to be one wheel housing per car so that no car can be decoupled and driven away because the one it was coupled to would be left without a "leg to stand on". I've seen this done before with regular train cars. It's for building on the cheap. Two use one. If a car needs to go to the shop, the whole train goes and gets decoupled there. No decoupling in the field.

This is the skeleton on which the passenger compartment rests.

monoskel.gif - 7kb

Note that there is only one wheel box (A) fixed to each car which connects to the next car by a hinge & pin mechanism (like a door). The main engine car would, of course be more elaborate with more drive wheels at both ends so that it would be completely independent.

monoslop.gif - 2kb
The amount of play in the frame (the distance from the inside of the frame to the side of the rail) determines the maximum radius of curvature of the rail itself. I would like the passenger car to be able to move on a circle with a diameter no bigger than a football field.

I've considered the idea that the passenger cars should be passive (motorwise) but I've reconsidered because I don't think that the engine car would be able to pull the entire train up a slight grade ... if ... it was running in a freezing rain ... and ... my system MUST operate in all weather ... and most certainly when all automobile traffic is halted. Nothing short of a tornado should be able to stop this system. Hence, the passenger cars would be equipped with a smaller auxiliary electric motor to assist the main engine in bad weather or in the event the main engine died.

The Rail

Here is a cross-section of the track on which the cars run.

monotrak.gif - 6kb Note that I've paid some attention to water. The top is slightly curved so that rain runs off. It drips down and in general does not hit the base. The electrical contact rail is well hidden under the overhang. And ... I realized that if I strengthened the beam with an inside box design, I could "sell" or rent the resulting empty space for communications cables.

A grooved electrical track (red) is affixed to the underside of the rail to take power to all the trains electrical systems. A flexible metal rod or band runs in this track, sprung against the track. Of course, it must be insulated from the metal rail itself.

The lower drive wheels contact the sides of the track where traction is increased by pressing the wheels from each side. They provide auxiliary power for going up grades or when the upper track is slippery as in an ice storm. Even in the worst weather, one side or the other is certain to be clear. They can also serve as brake / generators and could feed power to backup batteries in the main engine car.

monotrk2.gif - 6kb

The main drive wheel on top is the largest (not completely shown) and presses with the weight of the car and passengers. There are two non-motorized, guide wheels to insure that the upper wheel doesn't drift to the side when the load is unbalanced. These are all solid, "hard" rubber wheels. I do not think it is necessary to install any kind of spring-shock absorber mechanism because the track should be fundamentally smooth. But maybe I'm wrong ... in which case some sort of shock absorber would have to be installed.


There are emergency stationary brakes at all train stations and a few other places where needed. These consist of a stationary brake rail the raises up to engage the brake pads on the underside of each car. The stationary rail lifts the weight of the cars off the wheels which stops the car when the stationmaster or traffic controller activates them by remote control.

monobrak.gif - 6kb

I have also designed these "inertial brakes". I haven't seen them before but I suppose there is nothing new under the sun ... ;o) This is tricky so pay attention.

As the driver manually pulls on the brake, the engine begins to slow down. This causes the cars he is pulling to press against the engine thereby compressing the distance between the engine and first car. This distance (shown schematically and larger than scale) can be mechanically utilized to press the red brake pads against the side of the rail where the auxiliary drive wheels of each car engage. So we get the inertia of the second car forcing its emergency brake pads directly against the rail. And so on ... down the line of cars. A small manual pull by the driver initiates a cascade of braking by each subsequent car.

monobrk2.gif - 7kb

By mechanically controlling the lengths and leverages involved, one can stop an entire train with the pressure of a fingertip by using the inertia of the train against its forward motion. Phewwwwww ... did you get lost in there? It seems a little screwy ... but it should work.

This is an emergency brake controlled by the driver in case his power goes out. The primary brake is the re-generation of electricity by turning the auxiliary drive motors (and engine motors) into generators of electricity instead of consumers. This energy can then be returned to the power grid or used to accelerate the train after stopping.

Braided rails

A monorail train at Disneyland seems to work alright. However, it would not work well in the real world because it is not sufficiently dependable. If a ride in Disneyland fails, they simply shut it down till repairs can be implemented while offering alternate transportation. If our system fails, it would be catastrophic as would be the case if New York's subway system failed.

The longer the system, the more likely that some part will fail causing an unacceptable delay. If riders are to use the system to get to work it must be absolutely dependable (or as near perfect as humanly possible).

The solution is redundancy. There must be more than one rail.

I propose that two systems exist side by side ... one local and one going longer distances ... interconnected by switches. So that, in the event of a failure, trains can be rerouted down the local line around the obstruction, then back to the main track. In this way, the rider is maximally assured that he can get to work each and every day with minimal expectation of having to use alternate transportation, i.e. his own car.

monobrad.gif - 6kb

Here, both local and distance travel a circular route in the same direction with connections between them. Such a "braided" system has two kinds of switches ... the merge switch and the split switch. Both have identical machinery but the traffic flows in the opposite direction.

If there is a problem between A and B on the main line, a non-local train detours at A and re-enters the long distance track at B ... utilizing the local track to facilitate uninterrupted flow. As much as possible, local and long distance would stay on the assigned track during rush hour. At non-peak times any route deemed useful is possible.

The Switches

These are simple straight lengths of track, fixed at one end and movable at the other so that one track can lead to two alternatives (possibly more if necessary). monoswit.gif - 4kb Note: I drew the yellow track on which the movable rail rides, too close to the rail. But you get the picture.

Along with the switch, a brake rail must rise up on the track to stop any train arriving at the intersection at the inopportune moment, i.e. an accident. This is a fairly straightforward device used in theme park rides. As the train pulls into a station, a device rises up next to the regular rail which picks the cars up off their wheels and onto a friction bar causing the train to stop without fail.

Rail construction

As I conceive of it, the rail upon which the train runs, should not be solidly fixed to anything at all. Because it is made of steel, it must expand and contract about a quarter inch per 40' length depending on the extremes of temperature. I propose the following design which allows for expansion and ease of construction. monoplat.gif - 5kb Here, a Base Plate is welded to the Stalk which holds up the track. The stalk may be anything from a basic 16 feet tall to 40 or even more. The details are left to the engineers who can figure out how robust it must be for the given weight to be supported and length of track. I would be looking for "cheap" rather than aesthetics or course. A simple I-beam embedded in concrete would do nicely.

A hole is dug at the appropriate place (standardized to the greatest degree possible) and the stalk dropped in with concrete. When it's ready ... here comes the track.

We slip one end of the track under the Hold "A"s and at the next stalk, the other end rests between the Hold "B"s. In this way, no welding is necessary and the track is just laid in place with about a quarter inch gap for expansion.

monojoin.gif - 4kb
To complete locking the track in place, each section of track will have welded to one end "guide plates" as shown. This end of the rail sits between the non-locking "B" holds and the next rail is slid into the "A" holds and over the guide plates of the rail already in place. Now, both ends of any rail are locked down without any welds.

A small spacer would be temporarily placed between the two rails to provide the quarter inch expansion gap where they meet at (A). And at C, a small metal "stopper" block is welded under each rail so that it cannot slide through the A and B holds causing one rail to fall down. If this were not done, eventually, with the passage of many trains in one direction, the rails would "move on down the line" being pushed by those trains ever so slightly ... but cumulatively.

To do maintenance on one section of finished track, a rail would have to be "torched out" in order to remove subsequent rails from the line. You couldn't just pull one out ... they are "locked" in yet not connected ... like Borromean Rings.


Going from one "stalk" to the next on flat land is simply a matter of deciding on the lowest cost design given the weight carried. In the case of one of my trains, the weight should be about 5-6000 pounds per car with passengers included. So, about 30 tons per train and add another 5 tons for the engine car. Figure about 35 tons spread over 200 feet of track length.

The height of the rail over the ground should be about 20 feet so that tractor-trailers can pass underneath with plenty of clearance on surface streets. This design should be the same throughout to facilitate standardization. Here are three basic examples.

monostlk.gif - 6kb

On the top is my simplest design where all the riding rails are "locked" together but not welded or bolted. The lower designs leave more empty space underneath but the triangular sections are welded or bolted together.

Getting from one "stalk" to the next presents many problems when obstacles are encountered. Rails have to rise up and over some things ... like freeways and interchanges or even rivers and such. This requires rails with double curvatures (upward and downward), i.e. more expensive.

Here is my bridge over the river "Qwi". I don't have to spell it right ... because ... it's my bridge.

monobrdg.gif - 9kb
The excellent thing about mounting the rail on top of the truss is that when you look out the window of a train car ... you wouldn't be able to see anything at all. So, you would have the sensation of "flying" over the river when at the highest point where the truss is thinnest. That alone would be worth the price of admission (which is going to be nothing ;o).

Getting up and over obstacles has many solutions. I shall always favor the cheapest. This always looks the cleanest to me. PS. When I say cheap ... I don't mean unsafe ... just ... "without non-functional additions", e.g. artwork, etc. ... unless they are really, really cheap!

The Train Station

We need to pick up about 15,000 people in three hours and take them to work. Because this represents about 15,000 cars also, we need 15,000 parking spaces. Clearly, if they are all in one place, it will be one humungous parking lot. One might have to walk half a mile just to get from one's car to the train. And ... it will be much farther to drive there from home on the average.

So, I've decided on lots of not more than 1000 cars. We need 15 of them. Fifteen train stations for picking people up to take them to work ... from the suburbs mostly. They will be long stations, not square and will accomodate just one train at a time. So the interior loading platform will be about 200 feet long at about 3 feet per passenger and 50 on each side ... plus room for the engine, space between cars, etc.

monostat.gif - 17kb

The rush hour loading-unloading station will always be near the level of the parking lot. No one is to have to climb stairs to get into the train itself. No steps. There will be something of a ramp up a foot or less to keep the station above any conceivable rainfall. The train tracks themselves will slope downward into the station and upward upon leaving. This is an open air station with a sloped, corragated, tin roof but not much in the way of sides (maybe a few windbrakers) ... something like a typical waiting area at an amusement park ride. Sometimes they have air conditioning that just leaks out the sides, some fans, maybe a radiant heater for colder days.

monosta2.gif - 7kb

The Local System

Train cars that travel on the local route must have two-person seats because the majority of people going somewhere other than work don't go alone. It's the same design just wider. And ... the seat backs should be movable so that four people can sit facing one another (as they do in commuter trains where you can push the back of the seat so as to sit facing forward or backward). Either trains must be able to travel on the other's track so that maximum use can be gotten out of the entire rail system at non-rush hour periods and on weekends.

A local station might be located at every big school, shopping mall and sports venue ... with extra spur tracks running to major sporting events to lighten the traffic load to and from the event. The local track should also stop at or near the main stations so that they can drop off rush hour passengers to change trains. This is not the favored "getting to work plan". If most passengers have to change trains and walk & wait ... the system would generally fail. Anyone who has ridden the subway in New York knows how time consuming it is to get where you want if you must change trains often. Still, if you live within walking distance of a local stop and can connect with the "long track", you have the option of seeking employment (or going to school) anywhere along the line even if you do not own an automobile.


During rush hour more trains and drivers are needed than at other times. So, there must be a parking lot for trains perhaps midway from their major pickup and dropoff points. Some trains will move constantly. Some might shift onto the local track and vice versa.

Where many cars are parked for the day, there must be attendants physically there to "watch" for theft and vandalism. Perhaps the drivers who are not needed between rush hours can mill around performing this function.

Lastly, can such a system ever be tried out ... realistically?

No. Not in America. Maybe in China. If I had Paul Allen's money, I'd build a few kilometers myself in some medium sized town to test it out at my own expense. Barring that ... forget about it. You will see monorails only in theme parks and running between government buildings.

But ...

I'm gonna' lay down on the floor
flail away with my arms and legs
and hold my breath till it happens
anyway ...


Ebtx Home Page