From planes to trains to automobiles, every mode of transportation is just a little bit different in MK2K.
A cross between a zeppelin and an ocean vessel, a skyship is a large metal vehicle that uses Feather Weight enchantments and technomagical antigravity generators to float in midair. These vehicles are usually propelled by turbojet engines, though for delicate maneuvers they use much larger versions of the drive turbines used in skimmers and swoops.
Because of their Feather Weight enchantments, skyships require relatively little fuel to propel what would otherwise be an enormous amount of weight. A single skyliner, with a dozen turbojet engines, can carry as much as an oceangoing cruise ship while traveling at speeds of up to 1000 km/hr. This makes them ideal for transporting large amounts of cargo, especially cargo that has to arrive quickly. Most skyships also have a passenger deck, where a few hundred paying customers can sit back and enjoy a roomy, relaxing flight to their destination. The ships stop at docking platforms that are elevated above the surrounding metropolis; here they sit, floating in midair on their antigrav cushions, as passengers exit through extended docking arms similar in appearance to the jetways at a mundane airport. The ships rarely actually come to rest anywhere, landing only when the engines and antigrav generators need to be serviced.
On the whole, skyships are a more cost-effective way of transporting people and cargo than traditional airplanes (which never became very popular in MK2K as a means of civilian transportation). When maximum economy and carrying capacity are desired, though, the best route is still the trustworthy ocean freighter.
For ground transportation across the Empire and Quenardya, the fastest and best means available is the maglev train. These are streamlined trains that use electromagnets to float above a track inside a closed tube, usually underground in cities and elevated on pylons in open country. (There are two additional guide rails at the upper corners of the tube, also equipped with electromagnets, so that the train is braced from all sides.)
The train has no direct contact with any solid surface, so the only friction it experiences is from wind resistance inside the tube. Vacuum pumps help to keep the air pressure in the tube down to about a third of normal atmospheric pressure, which reduces friction even more. The end result is that maglev trains are able to travel very, very fast -- up to 800 km/hr when riding cross-country.
Maglev lines link Metamor City with all major metropolitan areas in the Empire and Quenardya, with additional side-branches to Yesulam and Whales (the latter courtesy of one of the longest bridges in the world). Fares are relatively cheap for personal travel, thanks to the high volume of traffic, and this is the preferred method of cross-country and inner-city travel for most citizens of the Empire. Large amounts of cargo are also transported along the maglev lines.
Skimmers and Swoops
Swoops and skimmers are the primary means of transportation in Metamor City. Living in a metropolis that is, essentially, five layers of city stacked on top of each other leads to certain problems, not the least of which is how you can drive safely in that environment. Sure, the roads are all solid enough, but if you get forced off of the skyway during rush hour on the city's third level, you'd better be able to fly.
Enter the skimmer. Skimmers are the spiritual successor to the automobile (which is still in use in much of the rest of the world, by the way), essentially a hovercraft for two or more people that features an enclosed cabin. Swoops are descended from motorcycles, and can carry one or two people that are exposed to the elements as they ride in the vehicle's saddle. Swoops are faster and more maneuverable than skimmers, while skimmers are larger, safer, and more versatile.
Both skimmers and swoops use spelltech in order to fly and maneuver. In either case, the vehicle's engine is connected by frictionless driveshafts to a pair of long metal rods called drive turbines. (The engine is not physically connected to the turbines; each turbine is spun by the electromagnets in its driveshaft, which surrounds the turbine at a distance that allows it several inches of movement in any direction, for reasons that will become clear shortly.) These turbines are made from a special, highly durable type of steel made using Elven forging techniques, so they are especially durable, rust-resistant and easy to enchant. Each turbine holds four cylindrical disks along its length, each of which bears a variety of carefully-enchanted runes that are connected by the runes that run the length of the rod. Each turbine is connected to two piston-equipped control rods at either end, which can move either the front or back of the turbine left, right, up or down, within the limits of the range of motion allowed by the driveshaft.
The enchantments on the drive turbines are such that when they are spun, they weave a mana field that generates a repulsor field around the vehicle. This modified levitation spell causes the vehicle to push away from any solid or liquid mass that is not part of the vehicle, its passengers or its cargo. The field grows stronger the faster the turbines spin, so by varying the throttle the pilot can vary the strength of the repulsor's effect. Just what that effect is depends on the orientations of the turbines with respect to the vehicle and with respect to each other.
In the neutral position, the turbines sit side by side parallel to the long axis of the vehicle. In this mode, running at idle speeds, they will exert a repulsion force sufficient to hold the vehicle steady in the air. Increasing the speed of the turbines beyond idle will cause the vehicle to float upward (since there is more mass in the ground below the vehicle than in the air above it); throttling back to sub-idle will cause the vehicle to begin to fall downward. Safety mechanisms built into the flight computers of modern skimmers and swoops prevent them from crashing into the ground due to sub-idle turbines or turbine/engine failure; an emergency enchantment hidden within the vehicle triggers a shield spell that will gently break its fall when it nears the surface. This shield is like an airbag, in that it only works once; it must be recharged after every "crash". (Incidentally, the shield also greatly reduces the odds of traffic fatalities: it will work almost as well in a skimmer-to-skimmer collision as in a skimmer-to-ground collision.)
To move the vehicle forward, the control rods angle the rear ends of the turbines toward each other. This strengthens the repulsor field to the rear while weakening it to the front. The net result, by the Third Law of Mechanics, is that the vehicle is pushed forward with a force equal and opposite to the repulsion force being exerted on everything behind it. Similarly, angling the turbines inward at the front exerts a backward force, causing the vehicle to slow down (or accelerate in reverse).
To gain altitude, the control rods angle the turbines down in front and up in back; this increases the repulsion force in front, causing the nose of the vehicle to be pushed upwards. Nosing down requires the opposite movement.
To roll the vehicle, rotating it around its long axis, the control rods raise the turbine on one side and lower the turbine on the other side. The rod closer to the ground will exert the greater repulsion force, and as a result the vehicle will roll toward the side with the elevated turbine.
To yaw the vehicle, rotating it around its z-axis, both turbines must be kept parallel to each other and angled to the left or right with respect to the vehicle. Angling the front ends of the turbines to the right will exert a greater force in that direction, causing the vehicle to yaw to the left, and vice versa.
As noted above, spinning the turbines increases the repulsion force, and therefore the acceleration in the direction determined by their orientation; but the turbines need not be spun at the same speeds. If the left turbine is spun faster than the right turbine, it will exert a greater force than the right turbine; this will cause the vehicle to side-slip to the right.
These controls may sound somewhat confusing, but vehicle designers have found ways of making them intuitive. In modern skimmers, control is "fly-by-mind": a spelljack headset links the skimmer's flight computer directly to the mind of the pilot, allowing for rapid, natural maneuvering in all three dimensions and around all three axes. Swoops use the yoke, pedals and throttle method:
Older skimmers use a variety of control schemes: some based on joystick, throttle and rudder pedals, some based on a flight yoke and automobile-style pedals, and some based on stranger, hybrid techniques. Skimmers developed unevenly, growing out of the automobile industry, and there was much experimentation in the early years to determine which control system was easiest for drivers to use. The spelljack system is the first truly universal standard for skimmer controls since the vehicle's invention.
Skimmers and swoops were both invented around 1930 CR, only about four decades after the invention of the automobile. Of course, neither autos nor skimmers and swoops looked much like they do now in those days -- they've gone through many years of evolution and refinement. In any case, the development of skimmers and the growth of Metamor City have gone hand in hand; it wasn't until airborne personal transportation became truly practical that the city was able to really expand into the clouds. Since that time, however, the growth of Metamor City has been almost exponential.
Metamor City, like any large metropolis, requires large amounts of supplies on a daily basis -- and also produces large volumes of exports and a great deal of waste. Moving stuff into, around and out of the city is an effort that requires a multifaceted approach.
Inside the City
Within the city, cargo and trash are moved around at Street level in large ground-trucks, much like you would see in any modern town. Supplies are transported vertically in cargo elevators and waste chutes. Most garbage is recycled somewhere within city limits, and the remainder is either annihilated magically or shipped out to disposal sites. Organic waste is processed into fertilizer and sent back to the farming communities that grow the food.
When more direct transportation of goods between high-level skyways is required, skimmer-trucks and cargo tenders are used. The latter is a kind of miniature skyship -- too large for the skyways, but maneuverable enough to get close enough to the towers for direct on-loading and off-loading of merchandise. They have large, articulated manipulator arms for picking up cargo containers and moving them around. These tenders have to be registered with the city as air traffic, and carry transponders to allow their movements to be tracked. The largest ones can carry as much as three or four semi-trucks. In addition to ferrying loads of cargo between platforms, they are also used in loading and unloading skyships at the docking platforms.
Metamor City itself is landlocked, and widening the Metamor River into a channel big enough to handle shipping traffic would have been impractical and ecologically destructive. Instead, Metamor continues to receive shipping as it always has, at the nearby port-city of Menth.
Menth doesn't have the layer-cake structure of Metamor City proper, but it has become quite a busy city in its own right. Maglev trains move people and cargo back and forth between the ports and Metamor City. Some additional shipping traffic comes in at Meriton, formerly Sorin, though the latter city is better known nowadays as the birthplace of the Meraist Church.
Maglev trains don't actually have "rails", but a great deal of cargo is carried in on them in any case. This is generally very dense cargo that must be transported across land, and would weigh down the skyships too much for air travel: ore, steel, stone, gravel, etc. Pressurized liquids and gases are also transported in this fashion -- true, the tubes themselves are low-pressure, but the trains are at atmospheric pressure on the inside, even in the cargo holds (unlike a skyship). There are train stations throughout the city, a few of which are equipped for handling industrial cargo; these, of course, are all at Street-level.
Skyships are used for moving relatively light cargo, or at least cargo that's light with respect to its volume -- the Feather Weight enchantments can only counteract so much, after all. They're also especially good for moving highly perishable items. Meat, produce, grain, furniture and electronics are all common cargo on the skyships. All of the major skyship docking platforms are equipped with cranes and cargo tenders to assist in offloading freight.